Scroll compressor and air conditioner comprising same

Abstract

A scroll compressor is disclosed. The scroll compressor according to the present disclosure comprises: a housing; a fixed scroll provided in the housing; an orbiting scroll which is engaged with the fixed scroll to form a compression chamber; an injection hole formed in the fixed scroll; a recovery flow path connecting an oil separator and the injection hole; and a decompression device for adjusting the pressure of oil recovered from the oil separator.

Description

Scroll compressor and air conditioner including same

[0001] The present disclosure relates to a scroll compressor and an air conditioner including the same.

[0002] Air conditioners are used to maintain indoor air quality appropriate to the intended purpose. Typically, air conditioners utilize a refrigeration cycle, including a compressor, heat exchanger, and expansion valve, through which refrigerant can circulate, to cool or heat indoor air. Among these, the compressor compresses the refrigerant, and various types of compressors, such as piston compressors and scroll compressors, are used.

[0003] A scroll compressor is a compressor designed to reduce noise and increase compression efficiency. A fixed scroll and an orbiting scroll are interlocked to form a compression chamber, and the orbiting scroll rotates relative to the fixed scroll, thereby compressing and discharging the refrigerant while causing it to flow from the outermost part of the compression chamber to the center of the compression chamber.

[0004] Scroll compressors use oil to reduce friction on the sliding surfaces (slide faces) of the fixed and orbiting scrolls, as the scroll rotates, and to maintain airtightness in the compression chamber. This oil, after being compressed with the refrigerant, is discharged outside the compressor and circulates throughout the refrigeration cycle, potentially affecting the function and durability of the air conditioner. To address this issue, an oil separator is used. The separator separates the oil from the incoming compressed refrigerant mixed with oil.

[0005] Conventional scroll compressors have suffered from low oil recovery efficiency due to a small difference in pressure between the oil separator and the compressor when the separated oil is returned to the compressor. In particular, the oil is recovered through the suction pipe through which the refrigerant is sucked into the compressor, resulting in low compressor volumetric efficiency.

[0006] According to at least one embodiment of the present disclosure, a scroll compressor may include a housing, a fixed scroll provided inside the housing, an orbiting scroll interlocked with the fixed scroll to form a compression chamber, an injection hole formed in the fixed scroll, a recovery path connecting an oil separator and the injection hole, and a pressure reducing device for regulating the pressure of oil recovered from the oil separator.

[0007] The above-mentioned rotating scroll may be placed below the above-mentioned fixed scroll.

[0008] The above fixed scroll may include a fixed cap and a fixed wrap that protrudes from the fixed cap toward the rotating scroll and is formed in a spiral shape.

[0009] The above-mentioned orbiting scroll may include a orbiting plate having a shape of a disk and an orbiting wrap that protrudes from the orbiting plate toward the fixed scroll and is formed in a spiral shape.

[0010] The above injection hole can be formed to penetrate the fixed cap.

[0011] The above injection hole can communicate with the outermost compression chamber.

[0012] The above injection hole may have a diameter smaller than the thickness of the above turning wrap.

[0013] The above pressure reducing device is one of a capillary tube or an orifice pin and can be placed in the recovery path.

[0014] The above pressure reducing device is an orifice pin and can be placed in the injection hole.

[0015] Alternatively, the scroll compressor may include a housing, a fixed scroll provided inside the housing, an orbiting scroll interlocked with the fixed scroll to form a compression chamber, a main frame supporting the fixed scroll and the orbiting scroll, a recovery path for communicating an oil separator with an internal space of the housing, and a pressure reducing device for regulating the pressure of oil recovered from the oil separator.

[0016] The above main frame may include at least one intermediate pressure chamber formed by being sunken into the lower portion of the above rotating scroll.

[0017] The above recovery oil can be coupled to one side of the main frame so that one end is coupled to the oil separator and the other end is connected to the intermediate pressure chamber.

[0018] The above main frame may include an injection hole that connects the other end of the recovery path and the intermediate pressure chamber.

[0019] The above pressure reducing device can be placed in the injection hole.

[0020] Alternatively, the air conditioner according to the present disclosure may include a scroll compressor having a compression chamber formed inside a housing, an oil separator for separating oil from refrigerant flowing from the scroll compressor, a return path connecting the oil separator and the scroll compressor so that the oil separated from the oil separator is returned to the scroll compressor, and a pressure reducing device for regulating the pressure of the oil recovered from the oil separator.

[0021] The above scroll compressor may include a fixed scroll provided inside the housing and a rotating scroll disposed opposite one side of the fixed scroll.

[0022] The above fixed scroll may include a fixed cap, a fixed wrap formed in a spiral shape by protruding from one surface of the fixed cap, and an injection hole formed to penetrate the fixed cap.

[0023] Figure 1 is a drawing of an air conditioner to which a scroll compressor according to the prior art is applied.

[0024] FIG. 2 is a cross-sectional view of a scroll compressor according to one embodiment of the present disclosure.

[0025] FIG. 3 is an enlarged view of part A of FIG. 2 to explain a fixed scroll and a rotating scroll according to one embodiment of the present disclosure.

[0026] FIG. 4 is a drawing for explaining a process of recovering oil from an oil separator to a scroll compressor according to one embodiment of the present disclosure.

[0027] FIG. 5 is a cross-sectional view illustrating the location of an injection hole according to one embodiment of the present disclosure.

[0028] FIG. 6 is a rear view of a fixed scroll according to one embodiment of the present disclosure.

[0029] FIG. 7 is a drawing for explaining an injection hole according to one embodiment of the present disclosure.

[0030] FIG. 8 and FIG. 9 are drawings for explaining a pressure reducing device according to one embodiment of the present disclosure.

[0031] FIG. 10 is a drawing for explaining a pressure reducing device according to another embodiment of the present disclosure.

[0032] FIG. 11 is a drawing for explaining an injection hole according to another embodiment of the present disclosure.

[0033] FIG. 12 is a drawing for explaining a pressure reducing device according to another embodiment of the present disclosure.

[0034] FIG. 13 is a drawing for explaining an air conditioner according to one embodiment of the present disclosure.

[0035] It should be understood that the various embodiments and terms used in this document are not intended to limit the technical features described in this document to specific embodiments, but rather to include various modifications, equivalents, or substitutes of the embodiments.

[0036] In connection with the description of the drawings, similar reference numerals may be used for similar or related components.

[0037] The singular form of a noun corresponding to an item may include one or more of said items, unless the relevant context clearly indicates otherwise.

[0038] In this document, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" may include any one of the items listed together in that phrase, or all possible combinations thereof.

[0039] The term "and / or" includes any combination of a plurality of related described elements or any one of a plurality of related described elements.

[0040] Terms such as "first," "second," or "first" or "second" may be used simply to distinguish one component from another and do not qualify the components in any other respect (e.g., importance or order).

[0041] When a component (e.g., a first component) is referred to as being "coupled" or "connected" to another component (e.g., a second component), with or without the terms "functionally" or "communicatively," it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or through a third component.

[0042] The terms "include" or "have" are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in this document, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0043] When a component is said to be “connected,” “coupled,” “supported,” or “in contact with” another component, this includes not only cases where the components are directly connected, coupled, supported, or in contact, but also cases where the components are indirectly connected, coupled, supported, or in contact through a third component.

[0044] When we say that a component is "on" another component, this includes not only cases where the component is in contact with the other component, but also cases where there is another component between the two components.

[0045] Hereinafter, scroll compressors and air conditioners according to various embodiments will be specifically described with reference to the attached drawings.

[0046] Figure 1 is a drawing of an air conditioner to which a scroll compressor according to the prior art is applied.

[0047] Referring to FIG. 1, a conventional air conditioner may include a scroll compressor (1000) and an oil separator (2000).

[0048] In a conventional air conditioner, oil separated from the refrigerant in the oil separator (2000) can be recovered through an oil recovery pipe (2100) that connects the refrigerant supply pipe (1100) and the oil separator (2000). That is, the oil separated in the oil separator (2000) can be mixed with the refrigerant in the refrigerant supply pipe (1100) and introduced into the scroll compressor (1000).

[0049] Due to this, there was a problem in that the amount of refrigerant per unit time supplied to the scroll compressor (1000) was reduced, thereby lowering the compression efficiency of the scroll compressor (1000). A detailed description of the compression efficiency of the compressor will be described later in the description of Table 1.

[0050] Fig. 2 is a cross-sectional view of a scroll compressor according to one embodiment of the present disclosure. Referring to Fig. 2, the scroll compressor (1) includes a housing (10), a fixed scroll (20), an orbiting scroll (30), a compression chamber (40), a shaft (50), a main frame (60), and a motor (70).

[0051] A scroll compressor (1) is a device for compressing refrigerant sucked in through an inlet (11) and discharging it through an outlet (12).

[0052] The suction port (11) is configured to suck refrigerant from the outside of the scroll compressor (1) into the inside of the scroll compressor (1). The suction port (11) can be formed on one side of the housing (10).

[0053] The discharge port (12) is configured to discharge refrigerant from the inside of the scroll compressor (1) to the outside of the scroll compressor (1). The discharge port (12) may be formed on one side of the housing (10).

[0054] However, the location where the suction port (11) and the discharge port (12) are formed is not limited to this, and may be provided in other areas of the housing (1) depending on the case.

[0055] The discharge pipe (13) is configured to flow the refrigerant compressed in the scroll compressor (1) into the refrigeration cycle. One end of the discharge pipe (13) can be connected to the discharge port (12), and the other end can be connected to an oil separator (2, see Fig. 4).

[0056] An oil storage space (14) may be formed at the bottom of the scroll compressor (1). The scroll compressor (1) forms a compression chamber (40) while rotating with a fixed scroll (20) and an orbiting scroll (30) engaged with each other. Oil may be used to reduce friction of the sliding surfaces between the fixed scroll (20) and the orbiting scroll (30). The space for storing the oil used at this time may be the oil storage space (14) described above.

[0057] An oil path (51, 52) may be formed on the shaft (50) to supply oil stored in the oil storage space (14) between the fixed scroll (20) and the rotating scroll (30).

[0058] The shaft (50) is configured to rotate the orbiting scroll (30). The shaft (50) may be arranged on the central axis (X) of the scroll compressor (1). The orbiting scroll (30) may be coupled to the shaft (50) by being deflected in one direction from the center of the shaft (50). That is, the central axis (Y) of the orbiting scroll (30) and the central axis (X) of the scroll compressor (1) may not coincide. The shaft (50) may transmit power generated by the operation of the motor (70) to the orbiting scroll (30). Accordingly, when the shaft (50) rotates, the orbiting scroll (30) may perform a rotational movement about the central axis (X). At this time, the rotation direction of the orbiting scroll (30) may be clockwise, but is not limited thereto. Meanwhile, the center of the fixed scroll (20) can be arranged to be on the central axis (X) of the scroll compressor (1), so that when the shaft (50) rotates, the orbiting scroll (30) can perform an orbiting motion with respect to the fixed scroll (20).

[0059] The oil passages (51, 52) are configured to supply oil from the oil storage space (14) toward the fixed scroll (20) and the rotating scroll (30). The oil passage (51) may be formed in a spiral shape that wraps around the shaft (50) while rising. When the shaft (150) rotates, the oil passage (51) can transfer oil from the oil storage space (14) toward the scrolls (20, 30).

[0060] In this way, as the shaft (50) rotates according to the operation of the motor (70), the orbiting scroll (30) is rotated with respect to the fixed scroll (20), and at the same time, oil can be transferred from the oil storage space (14) to the scrolls (20, 30). Therefore, the orbiting scroll (30) rotates with respect to the fixed scroll (20), and friction on the sliding surface with respect to the fixed scroll (20) can be reduced. As a result, the amount of wear on the sliding surfaces of the fixed scroll (20) and the orbiting scroll (30) can be reduced, and thus the period during which the fixed scroll (20) and the orbiting scroll (30) can be used can be extended. In addition, as oil flows between the fixed scroll (20) and the orbiting scroll (30), the airtightness of the compression chamber (40) can be increased.

[0061] The main frame (60) is configured to support the fixed scroll (20) and the orbiting scroll (30). The main frame (60) may be provided between the motor (70) and the orbiting scroll (30) on the inside of the housing (10). That is, one side of the main frame (60) may be arranged to face the lower surface of the orbiting scroll (30) and the other side may be arranged to face the upper surface of the motor (70). The main frame (60) may be formed in a shape that can be accommodated in the housing (10).

[0062] FIG. 3 is a drawing illustrating a fixed scroll and an orbiting scroll according to one embodiment of the present disclosure. Referring to FIG. 3, the fixed scroll (20) and the orbiting scroll (30) are arranged to face each other, thereby forming a compression chamber (40) therebetween. Below, the fixed scroll (20) and the orbiting scroll (30) will be described in detail.

[0063] The fixed scroll (20) is configured to accommodate the orbiting scroll (30) and form a compression chamber (40) together with the orbiting scroll (30). The fixed scroll (20) may include a fixed cap (21), a fixed wrap (22), and a flange (23).

[0064] The fixed cap (21) may be provided in a shape that can be accommodated in the housing (10). The fixed cap (21) may include a fixed cap upper portion (211) and a fixed cap side portion (212). The fixed cap upper portion (211) may be formed in the shape of a circular plate. The fixed cap side portion (212) may be formed to protrude toward the rotary scroll (30) along the periphery of the fixed cap upper portion (211). Accordingly, the fixed cap (21) may have an accommodation space (S) formed therein.

[0065] A fixed wrap (22) may be provided in the receiving space (S) of the fixed cap (21). The fixed wrap (22) is configured to form a compression chamber (40) together with a rotating wrap (32) to be described later. The fixed wrap (22) may protrude from the fixed cap (21) toward the rotating scroll (30) and may be formed in a spiral shape. Specifically, the fixed wrap (22) may be formed to protrude from the upper portion (211) of the fixed cap toward the rotating scroll (30). The fixed wrap (22) may be formed as a curved surface having a constant thickness and height, and may be arbitrarily manufactured during the design process of the scroll compressor (1). For example, the height of the fixed wrap (22) may be the same as the height of the side portion (212) of the fixed cap.

[0066] The fixed cap (21) may further include a refrigerant inlet (not shown) and a refrigerant outlet (not shown). The refrigerant inlet is configured to allow refrigerant to be introduced into the compression chamber (40) from the outside of the scroll compressor (1). The refrigerant inlet may be in communication with the suction port (11) provided in the housing (10). Accordingly, the refrigerant introduced into the scroll compressor (1) from the suction port (11) may flow into the compression chamber (40) through the refrigerant inlet. The refrigerant inlet may be provided on the side (212) of the fixed cap, but is not limited thereto.

[0067] The refrigerant discharge port is configured to discharge the compressed refrigerant to the outside of the compression chamber (40). The refrigerant discharge port may be connected to a discharge port (12) provided in the housing (10). Accordingly, the high-pressure refrigerant may be discharged from the compression chamber (40) to the outside of the scroll compressor (1) through the refrigerant discharge port and discharge port (12), and thereafter may flow to the refrigeration cycle through the discharge pipe (13). The refrigerant discharge port may be provided on the side of the fixed cap (212), but is not limited thereto.

[0068] The fixed scroll (20) can be combined with the main frame (60). Specifically, a flange (23) provided around the periphery of the fixed cap side (212) can be combined in contact with the main frame (60).

[0069] At least one coupling hole (231) may be formed in the flange (23). Accordingly, the fixed scroll (20) may be stably fixed to the main frame (60) by a bolt (2311) inserted into the coupling hole (231). However, the configuration inserted into the coupling hole (231) is not limited to a bolt, and other configurations may be inserted as needed to fix the fixed scroll (20) to the main frame (60).

[0070] The orbiting scroll (30) is configured to interlock with the fixed scroll (20) to form a compression chamber (40). The orbiting scroll (30) may be arranged below the fixed scroll (20) so as to be able to rotate with respect to the fixed scroll (20). That is, the orbiting scroll (30) may be arranged between the fixed scroll (20) and the main frame (60).

[0071] The turning scroll (30) may include a turning plate (31) and a turning wrap (32). The turning plate (31) may be formed in a shape that can be accommodated in the accommodation space (S) of the fixed cap (21). Specifically, the turning plate (31) may have a circular shape with a diameter smaller than the diameter of the upper portion (211) of the fixed cap. A coupling groove (311) may be formed at the center of the turning plate (31). The coupling groove (311) is configured to be coupled with one end (50a) of the shaft (50).

[0072] The orbital wrap (32) is configured to interlock with the fixed wrap (22) to form a compression chamber (40). The orbital wrap (32) may be formed to have a spiral shape by protruding from the orbital plate (31) toward the fixed scroll (20). The thickness and height of the orbital wrap (32) may correspond to the thickness and height of the fixed wrap (22).

[0073] The rotating wrap (32) of the rotating scroll (30) can be arranged to be accommodated in a receiving space (S) in which the fixed wrap (22) of the fixed scroll (20) is not formed.

[0074] As the orbiting scroll (30) rotates, the orbiting wrap (32) can form a first compression chamber (C1, see FIG. 7) together with the fixed cap side (212). Thereafter, as the orbiting scroll (30) continues to rotate, the orbiting wrap (32) can form a second compression chamber (C2, see FIG. 7) that moves toward the center of the fixed scroll (20) together with the fixed wrap (22). The volume of the second compression chamber (C2) can become smaller as it moves toward the center of the fixed scroll (20).

[0075] The refrigerant is drawn into the first compression chamber (C1) through the suction port (11) and the refrigerant inlet, and then the pressure can be increased while the volume is gradually reduced in the second compression chamber (C2) by the rotation of the orbiting scroll (30). As the refrigerant moves toward the center of the fixed scroll (20) in the second compression chamber (C2), the pressure increases and it can be discharged to the outside of the scroll compressor (1) through the refrigerant discharge port and discharge port (12).

[0076] Meanwhile, the first compression chamber (C1) and the second compression chamber (C2) are not always formed singly, and may be formed simultaneously according to the rotation of the rotating scroll (30).

[0077] Meanwhile, in order to prevent the rotation of the orbiting scroll (30), an anti-rotation ring (33) may be provided between the orbiting scroll (30) and the main frame (60). The anti-rotation ring (33) may be an Oldham ring, but is not limited thereto.

[0078] FIG. 4 is a drawing illustrating a process of recovering oil from an oil separator to a scroll compressor according to one embodiment of the present disclosure. Referring to FIG. 4, a scroll compressor (1) may be connected to an oil separator (2) via a discharge pipe (13) and a recovery path (100).

[0079] The oil separator (2) is configured to separate oil from the high-pressure refrigerant discharged from the scroll compressor (1). The high-pressure refrigerant can flow toward the oil separator (2) through the discharge pipe (13). If oil is mixed with the refrigerant, the refrigerant can be separated into refrigerant and oil in the oil separator (2). The refrigerant passing through the oil separator (2) can return to the scroll compressor (1) through the suction port (11) after going through the refrigeration cycle. A detailed description of the refrigeration cycle will be described later with reference to Fig. 13.

[0080] When the shaft (50) is rotated by the motor (70), oil flows from the oil storage space (14) toward the scroll (20, 30), and in the process of compressing the refrigerant in the compression chamber (40) according to the rotation of the orbiting scroll (30), the oil may flow into the compression chamber (40). In this case, the refrigerant and the oil flowing into the compression chamber (40) may be compressed together and discharged toward the oil separator (2). The mixed fluid of the refrigerant and oil flowing through the discharge pipe (13) may flow into the oil separator (2). The mixed fluid may be separated into oil and refrigerant inside the oil separator (2). The separated refrigerant may flow to the refrigeration cycle through the refrigerant passage (21). The separated oil may flow toward the scroll compressor (1) through the return passage (100).

[0081] The recovery path (100) is configured to recover oil separated from the oil separator (2) into the scroll compressor (1). One end (100a) of the recovery path (100) can be connected to the oil separator (2), and the other end (100b) can be connected to the scroll compressor (1).

[0082] In this way, the oil separated from the mixed fluid in the oil separator (2) can flow into the scroll compressor (1) through the recovery path (100), so that the amount of oil used can be reduced and the frequency of oil charging can be reduced.

[0083] Meanwhile, the power for the oil separated from the mixed fluid in the oil separator (2) to flow to the scroll compressor (1) may be due to the pressure difference within the tube of the recovery passage (100). Specifically, since the refrigerant on the oil separator (2) side is in a high-pressure state compressed in the compression chamber (40), the scroll compressor (1) side within the recovery passage (100) may be at a relatively low pressure. In this way, the oil may flow from the high-pressure oil separator (2) side to the low-pressure scroll compressor (1) side due to the pressure difference between the oil separator (2) side and the scroll compressor (1) side within the tube of the recovery passage (100).

[0084] However, if the pressure difference within the recovery path (100) is not sufficient, the oil separated from the mixed fluid in the oil separator (2) may not flow efficiently.

[0085] In addition, when the other end (100b) of the recovery path (100) is connected to the suction port (11) of the housing (10), the volumetric efficiency of the refrigerant flowing into the compression chamber (40) through the suction port (11) and the refrigerant inlet port (24) may be reduced. In addition, the compression efficiency may be reduced as the refrigerant flows into the compression chamber (40) mixed with oil. This is also a problem of the scroll compressor (1000, FIG. 1) according to the prior art.

[0086] To solve these problems, the scroll compressor (1) may further include an injection hole (26, see FIGS. 5 and 6), and the recovery path (100) may further include a pressure reducing device (110, see FIGS. 8 and 9).

[0087] FIG. 5 is a drawing for explaining the location of an injection hole according to one embodiment of the present disclosure. FIG. 6 is a rear view of a fixed scroll according to one embodiment of the present disclosure.

[0088] Referring to FIGS. 5 and 6, the fixed scroll (20) may further include an injection hole (26).

[0089] The injection hole (26) is configured to flow oil separated from the mixed fluid in the oil separator (2) and recovered to the scroll compressor (1) through the recovery path (100) into the compression chamber (40).

[0090] The injection hole (26) may be provided in one area of ​​the fixed scroll (20). In this drawing, the injection hole (26) is illustrated as being formed in the upper portion (211) of the fixed cap, but the location of the injection hole (26) is not limited thereto and may be formed in the side portion (212) of the fixed cap. Hereinafter, an embodiment in which the injection hole (26) is formed in the upper portion (211) of the fixed cap will be described.

[0091] Specifically, the injection hole (26) can be formed in the upper portion (211) of the fixed cap between the first portion (22a) and the second portion (22b) of the fixed wrap (22). The injection hole (26) can be formed to penetrate the upper portion (211) of the fixed cap. One end (26a) of the injection hole (26) can be opened toward the receiving space (S) of the fixed scroll (20), and the other end (26b) can be connected to the other end (100b) of the recovery path (100).

[0092] The accommodation space (S) between the first region (22a) and the second region (22b) of the above-described fixed wrap (22) may be a space in which the second region (32b) of the rotating wrap (32) is accommodated. The second region (32b) of the rotating wrap (32) may form a compression chamber (40) together with the second region (22b) of the fixed wrap (22), the upper portion of the fixed cap (211), and the rotating plate (31). That is, the injection hole (26) may be formed to communicate the compression chamber (40) and the recovery path (100).

[0093] That is, the oil separated from the mixed fluid in the oil separator (2) can be introduced into the compression chamber (40) through the recovery path (100) and the injection hole (26).

[0094] As the oil discharged together with the refrigerant from the scroll compressor (1) is separated in the oil separator (2) and returned to the compression chamber (40) through the injection hole (26), the volume flux of the refrigerant passing through the suction port (11) can increase compared to the case where the oil is returned to the suction port (11) that sucks the refrigerant. As a result, the volumetric efficiency and compression efficiency of the scroll compressor (1) can be increased compared to the conventional scroll compressor (1000, see FIG. 1). A detailed description of the volumetric efficiency and compression efficiency of the scroll compressor (1) will be described later with reference to FIG. 13.

[0095] FIG. 7 is a drawing for explaining an injection hole according to one embodiment of the present disclosure. Referring to FIG. 7, a compression chamber (40, C1, C2) can be formed together with a fixed scroll (20) as the rotating scroll (30) rotates.

[0096] Specifically, when the fixed scroll (20) and the rotating scroll (30) form the first compression chamber (C1), refrigerant can be introduced into the first compression chamber (C1) through the refrigerant inlet (24) of the fixed scroll (20).

[0097] The refrigerant pressure in the first compression chamber (C1) may have the lowest pressure among the pressures in the compression chamber (40). Oil recovered from the oil separator (2) may be introduced into the compression chamber (40) through the injection hole (26) formed in the upper portion of the compression chamber (40), i.e., the upper portion of the fixed cap (211).

[0098] Oil introduced into the compression chamber (40) can be evenly spread on the sliding surfaces of the fixed wrap (22) and the rotating wrap (32) as the rotating scroll (20) rotates. Accordingly, wear of the sliding surfaces caused by mutual friction between the fixed wrap (22) and the rotating wrap (32) as the rotating scroll (30) rotates can be slowed down.

[0099] Meanwhile, the diameter (D1) of the injection hole (26) may be smaller than the thickness (D2) of the orbiting wrap (22). Accordingly, as the orbiting scroll (30) rotates, the upper surface of the orbiting wrap (22) may come into contact with one end (26a) of the injection hole (26) to close the injection hole (26). In this case, the oil recovered from the oil separator (2) toward the scroll compressor (1) may be applied to the upper surface of the orbiting wrap (22) without flowing into the compression chamber (40). The oil applied to the upper surface of the orbiting wrap (22) may be evenly spread on the sliding surfaces of the orbiting wrap (32) and the fixed wrap (22) as the orbiting scroll (20) rotates, and the resulting effect is as described above.

[0100] After this, as the rotary scroll (30) continues to rotate, one end (26a) of the injection hole (26) is opened again toward the compression chamber (40), so that the oil separated from the oil separator (2) can flow into the compression chamber (40).

[0101] FIGS. 8 and 9 are drawings for explaining a pressure reducing device according to one embodiment of the present disclosure. Referring to FIGS. 8 and 9, the recovery path (100) may include a pressure reducing device (110).

[0102] The pressure reducing device (110) is configured to increase the pressure difference between the two ends (100a, 100b) of the recovery path (100). The pressure reducing device (110) may be either a capillary tube (1101) or an orifice pin (1102).

[0103] Figure 8 is a drawing showing a case where the pressure reducing device (110) is a capillary tube (1101). The capillary tube (1101) may be a tube having a diameter smaller than the diameter of the recovery path (100).

[0104] Oil separated from the mixed fluid in the oil separator (2) can flow into the tube of the recovery channel (100) by passing through one end (100a) of the recovery channel (100) provided at the lower side of the oil separator (2). Thereafter, the oil can flow to the other end (100b) of the recovery channel (100) where a lower pressure is formed than that of the one end (100a).

[0105] Meanwhile, a capillary tube (1101) may be provided in the middle region (100c) of the recovery channel (100). Since the diameter of the capillary tube (1101) is smaller than the diameter of the recovery channel (100), the flow rate of the oil passing through the capillary tube (1101) may increase compared to when it passes through the recovery channel (100d) before passing through the capillary tube (1101). The pressure of the oil passing through the capillary tube (1101) may be lower than the pressure of the oil passing through the recovery channel (100d) before passing through the capillary tube (1101). This is a phenomenon according to Bernoulli's theorem, which states that the cross-sectional area of ​​a tube through which a fluid passes and the velocity of the fluid are inversely proportional, and the velocity of the fluid and the pressure of the fluid are inversely proportional.

[0106] In this way, as the oil recovered from the oil separator (2) to the scroll compressor (1) passes through the capillary tube (1101), the pressure decreases, so the pressure difference between the two ends (100a, 100b) of the recovery path (100) can increase. Accordingly, the amount of oil recovered from the oil separator (2) to the scroll compressor (1) can increase.

[0107] Figure 9 illustrates an embodiment in which the pressure reducing device (110) is an orifice pin (1102).

[0108] The orifice pin (1102) may be provided within the tube of the recovery passage (100) and may include a pin portion (1102a) and a head portion (1102b). The orifice pin (1102) may be arranged such that the head portion (1102b) faces the other end (100b) of the recovery passage (100).

[0109] The orifice pin (1102) may be formed such that the diameter (R2) of the pin portion (1102a) is smaller than the diameter (R1) of the recovery channel (100). Accordingly, the conduit of the recovery channel (100) through which oil flowing from one end (100a) to the other end (100b) of the recovery channel (100) can pass may be narrowed by the pin portion (1102a) of the orifice pin (1102). That is, since the cross-sectional area of ​​the recovery channel (100) through which the oil passes becomes smaller, the pressure of the oil passing through the orifice pin (1102) may be lower than the pressure of the oil before passing through it according to the Bernoulli's law described above. Accordingly, the oil may be efficiently recovered from the oil separator (2) to the scroll compressor (1).

[0110] FIG. 10 is a drawing for explaining a pressure reducing device according to another embodiment of the present disclosure. Referring to FIG. 10, the injection hole (26) may include a pressure reducing device (260).

[0111] The pressure reducing device (260) may be provided as an orifice pin, but its type is not limited thereto. In this embodiment, a case where the pressure reducing device (260) is an orifice pin will be described.

[0112] The pressure reducing device (260) is configured to increase the pressure difference between the two ends (100a, 100b) of the recovery path (100) to increase the flow rate and volume of oil flowing from the oil separator (2) to the scroll compressor (1). The pressure reducing device (260) may be provided inside the injection hole (26). The description of the injection hole (26) will be omitted to the extent that it overlaps with the description in FIGS. 5 and 6.

[0113] The pressure reducing device (260) may include a pin portion (260a) and a head portion (260b). The diameter of the pin portion (260a) of the pressure reducing device (260) may be smaller than the diameter of the injection hole (26). As a result, the cross-sectional area through which the fluid can flow in the injection hole (26) may be reduced by the pressure reducing device (260). That is, when the oil passes through the injection hole (26) while flowing from the oil separator (2) to the compression chamber (40), the flow velocity may increase and the pressure may decrease.

[0114] In this way, when a pressure reducing device (260) is provided inside the injection hole (26), the difference in internal pressure between one end (100a) of the recovery path (100) connected to the oil separator (2) and the injection hole (26) can increase, so that oil recovery from the oil separator (2) to the scroll compressor (1) can be facilitated.

[0115] Fig. 11 is a drawing for explaining an injection hole according to another embodiment of the present disclosure. Referring to Fig. 11, the main frame (60) may include an annular recessed portion (61) on the upper side of the rotating scroll (30).

[0116] The annular depression (61) can form a separate back pressure chamber (C3) together with the fixed scroll (20) and the orbiting scroll (30). The separate back pressure chamber (C3) is a space in which oil that flows from the oil storage space (14) toward the scroll (20, 30) through the oil passages (51, 52) by the rotation of the shaft (50) can be filled. The oil filled in the separate back pressure chamber (C3) can be supplied to the sliding surface between the orbiting scroll (20) and the fixed scroll (30) while the orbiting scroll (30) rotates.

[0117] Meanwhile, in the present embodiment, the main frame (60) may further include an injection hole (62). The purpose of the injection hole (62) is as described in FIGS. 5 and 6, so it will be omitted. The injection hole (62) may be formed to communicate the other end (100b) of the recovery path (100) and the annular recessed portion (61) of the main frame (60). That is, one end (62a) of the injection hole (62) may be connected to the other end (100b) of the recovery path (100), and the other end (62b) of the injection hole (62) may be opened toward a separate back pressure chamber (C3).

[0118] Due to this, different pressures may be formed inside the two ends (100a, 100b) of the recovery path (100). Specifically, the oil separated in the oil separator (2) may be high-pressure oil compressed in the compression chamber (40), while the oil filled inside the separate back pressure chamber (C3) may be low-pressure oil supplied from the low-pressure space (14, see FIG. 2). Therefore, the pressure at one end (100a) of the recovery path (100) may be higher than the pressure at the other end (100b). In this way, due to the pressure difference between the two ends (100a, 100b) of the recovery path (100), the oil inside the recovery path (100) may flow from the one end (100a) to the other end (100b).

[0119] FIG. 12 is a drawing illustrating a pressure reducing device according to another embodiment of the present disclosure. Referring to FIG. 12, the injection hole (62) may further include a pressure reducing device (620). The pressure reducing device (620) may be an orifice pin, and in this case, may include a pin portion (620a) and a head portion (620b). The description of the case where the pressure reducing device (620) is an orifice pin is the same as that described in FIG. 10, and therefore, a detailed description thereof will be omitted to the extent that it overlaps.

[0120] The pressure reducing device (620) may be arranged such that the head portion (620b) faces the separate pressure chamber (C3) and the pin portion (620a) faces the other end (100b) of the recovery passage (100). As a result, the cross-sectional area of ​​the conduit through which oil passes within the injection hole (62) may be reduced, and as a result, relatively lower-pressure oil may pass through the other end (62b) of the injection hole (62) than through the first end (62a). As a result, the oil within the recovery passage (100) may be efficiently recovered from the oil separator (2) to the scroll compressor (1).

[0121] FIG. 13 is a drawing for explaining an air conditioner according to one embodiment of the present disclosure. Referring to FIG. 13, the air conditioner (3) may include a scroll compressor (310), an oil separator (320), a recovery path (330), a pressure reducing device (340), a condenser (350), an expansion valve (360), and an evaporator (370).

[0122] A scroll compressor (310) may include a housing (311), a fixed scroll (312), an orbiting scroll (313), a shaft (314), a main frame (315), and a motor (316).

[0123] A compression chamber (380) may be formed inside the scroll compressor (310). An oil separator (320) may separate oil from the refrigerant flowing from the scroll compressor (310).

[0124] The recovery path (330) can connect the oil separator (320) and the scroll compressor (310) so that the oil separated from the oil separator (320) is recovered to the scroll compressor (310).

[0125] The pressure reducing device (340) is configured to control the pressure of oil recovered from the oil separator (320).

[0126] A fixed scroll (312) may be provided on the inside of the housing (311). A rotating scroll (313) may be arranged opposite one surface of the fixed scroll (312).

[0127] The fixed scroll (312) may include a fixed cap (3121), a fixed wrap (3122) formed in a spiral shape by protruding from one surface of the fixed cap (3121), and an injection hole (3123) formed to penetrate the fixed cap (3121).

[0128] In the air conditioner (3), the refrigerant can be compressed into a high-pressure refrigerant in the compression chamber (380) of the scroll compressor (310) and separated from the oil in the oil separator (320). Thereafter, the refrigerant can be liquefied while passing through the condenser (350). The liquid refrigerant can exchange heat with the surrounding air while passing through the expansion valve (360) and be vaporized again in the evaporator (370) to change into a low-pressure gaseous state. The gaseous refrigerant can be introduced back into the scroll compressor (310) and the same process can be repeated. This refrigerant circulation process is referred to as a refrigeration cycle.

[0129] The efficiency of the refrigeration cycle may be proportional to the compression efficiency of the scroll compressor (310). The compression efficiency of the scroll compressor (310) may be proportional to the volumetric efficiency and energy efficiency. That is, the higher the volumetric efficiency and energy efficiency of the scroll compressor (310), the higher the compression efficiency of the scroll compressor (310), and accordingly, the efficiency of the refrigeration cycle may also be increased. Hereinafter, the volumetric efficiency and energy efficiency of the scroll compressor (310) will be described.

[0130] The volumetric efficiency of the scroll compressor (310) can be calculated by comparing the energy consumed and the amount of refrigerant compressed. Specifically, the volumetric efficiency of the scroll compressor (310) can be a value obtained by comparing the actual mass flow rate of the refrigerant passing through the scroll compressor (310) with the theoretical mass flow rate value.

[0131] The actual mass flow rate may be the product of the density of the refrigerant passing through the scroll compressor (310) per unit time, the cross-sectional area of ​​the space through which it passes, and the flow rate of the refrigerant. The theoretical mass flow rate may be a theoretical value calculated by the stroke volume, and may be a value that excludes variables that occur when passing through the actual compressor.

[0132] That is, if a substance other than the refrigerant is mixed in the refrigerant flowing into the scroll compressor (310), the actual mass flow rate of the refrigerant passing through the scroll compressor (310) may differ significantly from the theoretical mass flow rate. Conversely, as the mixing ratio of the substance other than the refrigerant in the refrigerant flowing into the scroll compressor (310) decreases, the actual mass flow rate of the refrigerant may come closer to the theoretical mass flow rate.

[0133] In summary, the smaller the difference between the actual mass flow rate and the theoretical mass flow rate of the refrigerant, the more the volumetric efficiency of the scroll compressor (310) can increase.

[0134] In the case of conventional scroll compressors, the oil separated and recovered in the oil separator was recovered through a refrigerant supply pipe that introduced refrigerant into the interior of the scroll compressor, so there was a problem in that a large amount of oil, which is a substance other than refrigerant, was mixed in the refrigerant introduced into the scroll compressor (310), thereby lowering the volumetric efficiency described above.

[0135] In contrast, in the air conditioner (3) according to the present embodiment, since both ends (330a, 330b) of the recovery path (330) that allows the oil separated in the oil separator (320) to be recovered to the scroll compressor (310) are directly connected to the oil separator (320) and the injection hole (3123) of the fixed scroll (312), even if the amount of recovered oil increases, it may not affect the amount of refrigerant flowing into the scroll compressor (310).

[0136] Accordingly, the volumetric efficiency of the scroll compressor (310) is not lowered, so that it can have a higher volumetric efficiency than a conventional scroll compressor.

[0137] As a result, the compression efficiency of the scroll compressor (310) can be increased, thereby improving the efficiency of the refrigeration cycle. In addition, when a decompression device (340) is arranged in the injection hole (3123), oil recovery from the oil separator (320) to the scroll compressor (310) can be facilitated.

[0138]

[0139] Table 1 illustrates experimental results for the volumetric efficiency of a scroll compressor (310) in an air conditioner (3) according to one embodiment of the present disclosure. The Y-axis of Table 1 represents the rate of change in the volumetric efficiency of the scroll compressor (310), and the X-axis represents RPS (Rotations Per Second, the number of rotations per second of the scroll compressor). Specifically, the rate of change in volumetric efficiency of Table 1 is illustrated based on the performance of a single scroll compressor that does not include a decompression device and an injection hole according to the present disclosure and a configuration for recovering oil to a refrigerant supply pipe in a conventional scroll compressor, which is 100%. The performance of the compressor can be interpreted as the compression efficiency of the compressor, i.e., the volumetric efficiency.

[0140] When the RPS is 30, the scroll compressor (310) according to the present disclosure can achieve about 98.8% of the performance of a single scroll compressor. In contrast, the conventional scroll compressor (1000, see FIG. 1) can achieve about 96.4% of the performance of a single scroll compressor.

[0141] When the RPS is 60, the scroll compressor (310) according to the present disclosure can achieve about 99.7% of the performance of a single scroll compressor. In contrast, a conventional scroll compressor can achieve about 95.9% of the performance of a single scroll compressor.

[0142] When the RPS is 90, the scroll compressor (310) according to the present disclosure can have a performance of about 100.2%, which is higher than the performance of a single scroll compressor. On the other hand, the conventional scroll compressor can have a performance of about 96.9%. Here, the reason why the scroll compressor (310) according to the present disclosure has a result of implementing a performance higher than the performance of a single scroll compressor is that the compression chamber (380) is sealed as the oil recovered from the oil separator (320) is supplied to the sliding surfaces of the fixed scroll (312) and the orbiting scroll (313), thereby increasing the airtightness of the compression chamber (380).

[0143] As described above, when having the same RPS value, the scroll compressor (310) including the pressure reducing device (340) and the injection hole (3123) according to the present disclosure may have a smaller decrease in volumetric efficiency of the scroll compressor (310) compared to a conventional scroll compressor that recovers oil through a refrigerant inlet pipe. This means that the refrigeration cycle efficiency of the air conditioner (3) of the present disclosure is high.

[0144]

[0145] Table 2 shows the experimental results for the EER (Energy Efficiency Ratio) of the scroll compressor (310) in the air conditioner (3) according to one embodiment of the present disclosure. The Y-axis of Table 2 represents the rate of change in the EER of the compressor, and the X-axis represents the RPS.

[0146] An EER change rate of 100% means that the EER is the same as that of a single scroll compressor, as described in Table 1.

[0147] That is, according to Table 2, at the same RPS, the scroll compressor (310) according to the present disclosure has a smaller decrease in EER value compared to a single compressor than a conventional scroll compressor. This means that even when oil is recovered from an oil separator (320) to a scroll compressor (310) and supplied to a compression chamber (380), it can have an energy efficiency similar to that of a single scroll compressor. On the other hand, a conventional scroll compressor that recovers oil through a refrigerant supply pipe can only have a performance of about 96.1% to 98.7%, which is lower than the energy efficiency of a single scroll compressor.

[0148] Therefore, the air conditioner (3) according to the present disclosure can have higher energy efficiency compared to an air conditioner including a conventional scroll compressor.

[0149] In this way, the scroll compressor according to one embodiment of the present disclosure can directly recover oil discharged together with the refrigerant into the compression chamber or a separate back pressure chamber via an oil separator, thereby not affecting the flow rate of the refrigerant flowing into the compression chamber, thereby achieving high volumetric efficiency and energy efficiency. As a result, the performance of an air conditioner including the scroll compressor according to the present disclosure can be improved.

[0150] However, the scroll compressor according to the above-described embodiments may be used as a component of other devices requiring a compressor as well as devices requiring a refrigeration cycle, such as air conditioners.

[0151] Although various embodiments of the present disclosure have been individually described above, each embodiment does not necessarily have to be implemented alone, and the configuration and operation of each embodiment may be implemented in combination with at least one other embodiment.

[0152] In addition, although the preferred embodiments of the present disclosure have been illustrated and described above, the present disclosure is not limited to the specific embodiments described above, and various modifications may be made by a person having ordinary skill in the art to which the present invention pertains without departing from the gist of the present disclosure as claimed in the claims, and such modifications should not be understood individually from the technical idea or prospect of the present disclosure.

Claims

1. Housing; A fixed scroll provided on the inside of the above housing; A rotating scroll interlocked with the above fixed scroll to form a compression chamber; Injection holes formed in the above fixed scroll; A return path connecting the oil separator and the above injection hole; and A scroll compressor, comprising a pressure reducing device for controlling the pressure of oil recovered from the oil separator.

2. In paragraph 1, A scroll compressor wherein the above-mentioned rotating scroll is positioned below the above-mentioned fixed scroll.

3. In paragraph 1, The above fixed scroll is, fixed cap; and A fixed wrap is formed in a spiral shape and protrudes from the fixed cap toward the rotating scroll; The above rotating scroll is, A rotating plate having the shape of a disc; and It includes a rotating wrap that protrudes from the rotating plate toward the fixed scroll and is formed in a spiral shape; The above injection hole is, A scroll compressor formed to penetrate the above fixed cap.

4. In paragraph 3, The above injection hole is, A scroll compressor that connects the outermost compression chamber.

5. In paragraph 3, The above injection hole is, A scroll compressor having a diameter smaller than the thickness of the above-mentioned rotating wrap.

6. In paragraph 1, A scroll compressor, wherein the pressure reducing device is one of a capillary tube or an orifice pin and is disposed in the recovery path.

7. In paragraph 1, The above pressure reducing device is an orifice pin and is a scroll compressor disposed in the injection hole.

8. Housing; A fixed scroll provided inside the above housing; A rotating scroll interlocked with the above fixed scroll to form a compression chamber; A main frame supporting the fixed scroll and the rotating scroll; A return path for connecting the oil separator and the internal space of the housing; and A pressure reducing device for controlling the pressure of oil recovered from the oil separator; The main frame includes at least one intermediate pressure chamber formed by being sunken into the lower portion of the rotating scroll; A scroll compressor, wherein the above recovery oil is connected to one side of the main frame so that one end is connected to the oil separator and the other end is connected to the intermediate pressure chamber.

9. In paragraph 8, The above main frame includes an injection hole connecting the other end of the recovery path and the intermediate pressure chamber; The above pressure reducing device is a scroll compressor disposed in the injection hole.

10. Scroll compressor in which a compression chamber is formed inside the housing; An oil separator that separates oil from refrigerant flowing from the scroll compressor; A recovery path connecting the oil separator and the scroll compressor so that the oil separated from the oil separator is returned to the scroll compressor; and A pressure reducing device for controlling the pressure of oil recovered from the oil separator; The above scroll compressor, A fixed scroll provided inside the housing; and including a rotating scroll disposed opposite one side of the fixed scroll; The above fixed scroll is, fixed cap; A fixed wrap formed in a spiral shape by protruding from one side of the fixed cap; and An air conditioner, comprising an injection hole formed to penetrate the fixed cap.

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