Scroll Compressor

Abstract

The present invention comprises a casing; a main frame; a fixed scroll; and a rotary scroll, wherein the fixed scroll is provided with a discharge port, and the fixed side wall portion is provided with a first path portion extending by a predetermined distance from the top, having a flow path within which high pressure discharged from the discharge port can flow; and a second path portion provided at the bottom of the fixed side wall portion so as to be in communication with the first path portion and directed toward the side of the rotary scroll, wherein the upper part of the main frame is provided with a first back pressure chamber for forming an intermediate pressure, and the first back pressure chamber is provided with a scroll compressor capable of communicating with the second path portion.

Description

Technology Field

[0001] The present invention relates to a scroll compressor, and more specifically, to a scroll compressor having a structure capable of ensuring the performance and reliability of the compressor even in operating regions where back pressure is insufficient or behavior is unstable. Background Technology

[0002] In a scroll compressor, a rotating scroll and a non-rotating scroll are coupled together, and as the rotating scroll rotates relative to the non-rotating scroll, two pairs of compression chambers are formed.

[0003] The compression chamber consists of a suction pressure chamber formed on the outer edge, an intermediate pressure chamber formed continuously with gradually decreasing volume from the suction pressure chamber toward the center, and a discharge pressure chamber connected to the center of the intermediate pressure chamber. Generally, the suction pressure chamber is formed by penetrating the side of the non-rotating scroll, the intermediate pressure chamber is sealed, and the discharge pressure chamber is formed by penetrating the end plate portion of the non-rotating scroll.

[0004] Scroll compressors can be classified into low-pressure and high-pressure types depending on the path through which the refrigerant is drawn. In the low-pressure type, the refrigerant suction pipe is connected to the internal space of the casing, and the low-temperature suction refrigerant passes through the internal space of the casing before being guided to the suction pressure chamber. In the high-pressure type, the refrigerant suction pipe is directly connected to the suction pressure chamber, so that the refrigerant is guided directly to the suction pressure chamber without passing through the internal space of the casing.

[0005] In scroll compressors, the compression mechanism utilizes the pressure generated by the gas during the compression process to push the wrap; to overcome this, back pressure or tip seal methods are employed. Among these, tip seals have disadvantages in terms of performance and material costs, so a structure that uses back pressure to bring the wrap into contact is generally used. In this case, the back pressure is designed to be greater than the force generated by the gas to prevent the wrap from falling off. Depending on the location within the scroll compression section where the back pressure is applied, it can be classified into swirling back pressure and fixed back pressure methods.

[0006] The tip seal method requires the additional production of tip seal components, which raises issues regarding assemblability, reliability, and cost.

[0007] In addition, a high-pressure to low-pressure communication path inevitably occurs along the installation groove where the tip seal is mounted, and this results in losses.

[0008] In the fixed back pressure method, the number of parts constituting the back pressure chamber increases. In addition, thrust occurs in a double layer at the lap tip (or end plate) and the main frame, resulting in additional losses.

[0009] In the swirling back pressure method, since it is difficult to re-seal if rollover occurs due to insufficient back pressure during compressor operation, the back pressure level must be designed by considering the sealing force of the entire operating range. Consequently, excessive sealing force is applied at the efficiency point, leading to a decrease in compressor performance.

[0010] In a low-pressure scroll compressor structure where the motor is located at low pressure inside the housing, in order to axially seal the scroll compression part during the compression process, when the back pressure formed below the rotating scroll decreases, the back pressure hole opens and the refrigerant compressed again flows into the back pressure chamber to maintain the back pressure.

[0011] Patent Document 1 discloses a compressor having a lap tip thrust structure in which the end of the lap of the compression section becomes a thrust, and a back pressure hole is located at the end of the rotating scroll lap and is blocked by the bottom surface of the fixed scroll when the back pressure is high, but when the back pressure decreases, the back pressure hole opens through the gap between the end of the lap and the bottom surface so that the compressed refrigerant flows into the back pressure chamber through this hole.

[0012] In addition, Patent Document 2 discloses a configuration in which the back pressure is appropriately maintained by utilizing the back pressure outlet gap of the lower bearing so that the pressure inside the back pressure chamber is not excessively formed.

[0013] However, if the contact surface of the compression sections, i.e., the thrust, is a hard plate rather than a lap edge, a gap at the lap edge always exists, exposing the back pressure hole and causing constant flow, thereby making back pressure control impossible.

[0014] Therefore, since there are structures where the thrust must be of the end plate rather than the wrap end in some cases, there is a problem in that the back pressure control structure at the wrap end becomes impossible in these existing structures.

[0015] In addition, as with the existing structure, the surface area of ​​the central lap end must be larger than the back pressure hole area for machining to be possible, so this also poses a limitation.

[0016] In particular, in a structure in which a back pressure chamber is placed on the back side of a slewing scroll to form an axial seal of the compression section, if the pressure inside the back pressure chamber is lower than the set pressure, the back pressure decreases, causing the slewing scroll to be pushed backward, resulting in non-normal compression or reduced efficiency. The development of a structure to solve this problem is required. Prior art literature

[0017] US 8,998,595US 8,202,071 The problem to be solved

[0018] The present invention has been devised to solve the above-mentioned problem, and one objective of the present invention is to provide a structure in which, in a compressor having a plate thrust structure, high-pressure discharge gas can be introduced into the gap between contacting surfaces when a gap occurs between compression sections due to insufficient back pressure, thereby automatically regulating the back pressure. means of solving the problem

[0019] To solve the above problem, the scroll compressor of the present invention comprises: a casing; a main frame fixed inside the casing; a fixed scroll having a fixed side wall portion that forms a side wall to be supported on one side of the main frame; and a rotary scroll provided between the main frame and the fixed scroll, arranged to engage with the fixed scroll, with its side portion facing the fixed side wall portion to form a compression chamber, wherein the fixed scroll has a discharge port through which high pressure compressed in the compression chamber is discharged, and the fixed side wall portion has a first path portion that extends by a predetermined distance from the top, having a flow path through which high pressure discharged from the discharge port can flow inside; and a second path portion provided at the bottom of the fixed side wall portion to be communicable with the first path portion and directed toward the side of the rotary scroll, wherein a first back pressure chamber that forms an intermediate pressure is provided at the top of the main frame, and the first back pressure chamber is communicable with the second path portion.

[0020] The above fixed sidewall may further be provided with an intermediate connecting portion extending in a direction intersecting the first and second path portions between the first and second path portions.

[0021] The above fixed scroll is provided with a fixed flange portion extending radially from the bottom of the fixed side wall portion, and the intermediate connecting portion has one side penetrating from the outside of the fixed flange portion and the other side overlapping radially with the side of the rotating scroll, and a shielding portion may be installed on one side of the intermediate connecting portion.

[0022] The above-described rotating scroll comprises: a rotating plate portion positioned between the main frame and the fixed scroll and configured to rotate pivotally relative to the main frame and the fixed scroll; and a rotating wrap extending from the rotating plate portion toward the fixed scroll, wherein the lower end of the second path portion may be positioned to overlap with the outer side of the rotating plate portion.

[0023] The main frame comprises: a main flange portion in which a rotation axis is installed on the inner circumference; a scroll support portion provided on the inner side of the main flange portion and supporting the pivoting scroll in the axial direction; and a scroll fixing surface provided on the outer side of the main flange portion and supporting the fixed scroll in the axial direction, and the lower end of the second path portion may be disposed between the scroll support portion and the scroll fixing surface.

[0024] The above fixed side wall portion is further provided with a third path portion formed to be spaced outward from the second path portion and provided at the bottom of the above fixed side wall portion; and a communication control portion having a flow path that selectively opens and closes the second and third path portions between the first and third path portions, and the communication control portion may be provided with a pin that moves to selectively open and close the second and third path portions and an elastic member that elastically supports one side of the pin.

[0025] In the initial state of the elastic member, the pin blocks the third path, and in the compressed state of the elastic member, the pin can block the second path.

[0026] The above communication control unit may be formed in a direction intersecting the first path unit, the second path unit, and the third path unit.

[0027] The above fixed scroll is provided with a fixed flange portion extending radially from the bottom of the fixed side wall portion, and the communication control portion may be formed such that one side penetrates the outside of the fixed flange portion and the other side overlaps radially with the side of the pivoting scroll.

[0028] One side of the above communication control part is provided with a stopper that restricts the movement of the pin to the outside, and the pin can be positioned to block the third path part while in contact with and supported by the stopper.

[0029] The above third path section may overlap radially with one side of the above first back pressure chamber.

[0030] The first path section may be positioned radially between the second path section and the third path section.

[0031] The second path section may be formed radially inward from the first path section.

[0032] The main frame comprises: a main flange portion in which a rotation axis is installed on the inner circumference; a scroll support portion provided on the inner side of the main flange portion and supporting the pivoting scroll in the axial direction; and a scroll fixing surface provided on the outer side of the main flange portion and supporting the fixed scroll in the axial direction, and the lower end of the third path portion may be disposed between the outer circumference of the pivoting scroll and the scroll fixing surface. Effects of the invention

[0033] The scroll compressor of the present invention allows high-pressure discharge gas to flow into the gap between the contact surfaces of the fixed scroll and the rotating scroll when a gap occurs between the fixed scroll and the rotating scroll due to insufficient back pressure, thereby enabling the back pressure to be automatically regulated.

[0034] In the scroll compressor of the present invention, when the sealing force between the fixed scroll and the rotating scroll is sufficient, the second path section is blocked on the side of the rotating end plate section, thereby blocking the supply of high pressure to the first back pressure chamber; however, when the sealing force is insufficient and a gap is formed between the fixed scroll and the rotating scroll, the high-pressure refrigerant that escapes through the gap via the second path section can be supplied to the first back pressure chamber.

[0035] In the scroll compressor of the present invention, as a pin is installed in the communication control section so as to be supported by an elastic member, the high-pressure discharge refrigerant is prevented from flowing into the suction pressure side within the compression chamber by the pin blocking the second path section, and is able to flow to the first back pressure chamber (intermediate back pressure chamber) through the third path section.

[0036] The scroll compressor of the present invention enables the performance and reliability of the compressor to be secured even in operating regions where back pressure is insufficient or behavior is unstable.

[0037] In the scroll compressor of the present invention, high-pressure refrigerant can be accommodated in the intermediate communication section after passing through the first path section and before being supplied to the second path section, so that when a gap is formed between the lower side wall of the fixed scroll and the side of the rotating plate section due to a weak sealing force, the amount of high-pressure refrigerant supplied to the first back pressure chamber (intermediate pressure) can be further increased. Brief explanation of the drawing

[0038] FIG. 1 is a cross-sectional view illustrating a scroll compressor of the present invention. FIG. 2 is a cross-sectional view illustrating the compression section in FIG. 1. FIG. 3 is a cross-sectional view showing an enlarged view of one side of the compression section in a state where the sealing force is sufficient and no gap is generated. FIG. 4 is a cross-sectional view showing an enlarged view of one side of the compression section in a state where a gap is created due to insufficient sealing force. FIG. 5 is a cross-sectional view showing an enlarged view of one side of a compression part in a state where no gap is generated due to sufficient sealing force, as a compression part of another embodiment of the present invention. FIG. 6 is a cross-sectional view showing an enlarged view of one side of a compression section of another embodiment of the present invention, in which a gap is created due to insufficient sealing force and a pin blocks a third path section. FIG. 7 is a cross-sectional view showing an enlarged view of one side of a compression section of another embodiment of the present invention, in which a gap is created due to insufficient sealing force and a pin blocks a second path section. FIG. 8 is a cross-sectional view illustrating a compression section of another embodiment of the present invention, in which high pressure is supplied to the first back pressure chamber to supplement the back pressure so that no gap is generated. Specific details for implementing the invention

[0039] Hereinafter, a scroll compressor related to the present invention will be described in more detail with reference to the drawings.

[0040] In this specification, identical or similar reference numbers are assigned to identical or similar configurations even for different embodiments, and redundant descriptions thereof are omitted.

[0041] In addition, even if the embodiments are different, as long as there is no structural or functional contradiction, a structure applied to one embodiment can be applied identically to another embodiment.

[0042] A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0043] In describing the embodiments disclosed in this specification, if it is determined that a detailed description of related prior art could obscure the essence of the embodiments disclosed in this specification, such detailed description is omitted.

[0044] The attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and the technical concept disclosed in this specification is not limited by the attached drawings; it should be understood that all modifications, equivalents, and substitutions included within the concept and technical scope of the present invention are included.

[0045] FIG. 1 is a cross-sectional view illustrating a scroll compressor of the present invention, and FIG. 2 is a cross-sectional view illustrating a compression section in FIG. 1. FIG. 3 is a cross-sectional view illustrating an enlarged view of one side of a compression section in a state where no gap is generated due to sufficient sealing force, and FIG. 4 is a cross-sectional view illustrating an enlarged view of one side of a compression section in a state where a gap is generated due to insufficient sealing force.

[0046] Hereinafter, the scroll compressor of the present invention will be described with reference to FIGS. 1 to 4.

[0047] The scroll compressor of the present invention comprises: a casing (110); a main frame (130) fixed inside the casing (110); a fixed scroll (140) having a fixed side wall portion (143) that forms a side wall to be supported on one side of the main frame (130); and a pivoting scroll (150) that is provided between the main frame (130) and the fixed scroll (140), is positioned to engage with the fixed scroll (140), and is positioned so that its side faces the fixed side wall portion (143) to form a compression chamber.

[0048] The fixed scroll (140) has a discharge port (1411) through which high pressure compressed in the compression chamber (V) is discharged.

[0049] The fixed side wall portion (143) is provided with a first path portion (143a) that extends from the top by a predetermined distance, having a flow path through which high pressure discharged inside can flow; and a second path portion (143b) that is provided at the bottom of the fixed side wall portion (143) and is provided to face the side of the rotating scroll (150).

[0050] A first back pressure chamber (1312) that forms an intermediate pressure is provided at the top of the main frame (130), and the first back pressure chamber (1312) is connected to the second path section (143b).

[0051] As a result, if a gap occurs between the fixed scroll (140) and the rotating scroll (150) due to insufficient back pressure, high-pressure discharge gas can be introduced into the gap between the contact surfaces of the fixed scroll (140) and the rotating scroll (150) so that the back pressure can be automatically adjusted.

[0052] In particular, when a gap is created between the fixed scroll (140) and the rotating scroll (150) due to the pressure difference caused by the high-pressure discharge gas and the insufficient pressure in the back pressure chamber, the high-pressure discharge gas flows into the intermediate pressure chamber, thereby restoring the sealing force.

[0053] The restored sealing force refers to the force that causes the rotating scroll (150) to be pushed upward as high-pressure discharge gas is partially introduced into the intermediate pressure chamber, thereby sealing the side of the rotating scroll (150) and the lower end of the fixed side wall (143) of the fixed scroll (140) to seal each other.

[0054] As described above, the present invention has a thrust structure formed by the end plate of the pivoting scroll (150) and the lower side of the fixed scroll (140), and by controlling the back pressure in this end plate thrust structure.

[0055] As a result, the present invention allows back pressure and sealing force to be adjusted for various operating conditions of a scroll compressor, thereby enabling a wider operating range.

[0056] The scroll compressor of the present invention may be a scroll compressor having a rotating back pressure structure that provides back pressure on the rotating scroll (150) side.

[0057] The fixed side wall portion (143) may further be provided with an intermediate connecting portion (143c) extending in a direction intersecting the first and second path portions (143b) between the first path portion (143a) and the second path portion (143b).

[0058] In the intermediate connecting section (143c), high-pressure refrigerant can be accommodated after passing through the first path section (143a) and before being supplied to the second path section (143b). Accordingly, when a gap is formed between the lower side wall of the fixed scroll (140) and the side of the rotating plate section (151) due to a weak sealing force, the amount of high-pressure refrigerant supplied to the first back pressure chamber (1312) (intermediate pressure) can be increased.

[0059] As described below, the fixed scroll (140) is provided with a fixed flange portion extending radially from the bottom of the fixed side wall portion (143), and the intermediate connecting portion (143c) has one side penetrating from the outside of the fixed flange portion and the other side overlapping radially with the side of the pivoting scroll (150), and a shielding portion (143d) may be installed on one side of the intermediate connecting portion (143c). The shielding portion (143d) may be, for example, a shielding pin.

[0060] Due to the shielding section (143d), the high-pressure refrigerant that has passed through the first path section (143a) cannot escape to the outside of the fixed flange section and can flow along the intermediate connecting section (143c) toward the second path section (143b).

[0061] The second path section (143b) may be formed radially inward from the first path section (143a).

[0062] As a result, when the sealing force is sufficient, the supply of high pressure to the first back pressure chamber (1312) is blocked, and when the sealing force is insufficient and a gap is formed between the fixed scroll (140) and the rotating scroll (150), high pressure can be supplied to the first back pressure chamber (1312) through the gap.

[0063] As shown in FIGS. 2 to 4, the first path section (143a) and the second path section (143b) are formed in the axial direction, that is, in the up-and-down direction, and the intermediate connecting section (143c) can be formed in the radial direction, that is, in the left-right direction.

[0064] FIG. 5 is a cross-sectional view showing an enlarged view of one side of a compression section in a state where the sealing force is sufficient and no gap is generated, as in another embodiment of the present invention, and FIG. 6 is a cross-sectional view showing an enlarged view of one side of a compression section in a state where the sealing force is insufficient and a gap is generated, as in a state where the pin (143f) blocks the third path section (143i).

[0065] FIG. 7 is a cross-sectional view showing an enlarged view of one side of a compression section of another embodiment of the present invention when a gap is created due to insufficient sealing force and a pin (143f) blocks the second path section (143b), and FIG. 8 is a cross-sectional view showing a compression section of another embodiment of the present invention when high pressure is provided to the first back pressure chamber (1312) to supplement the back pressure and no gap is created.

[0066] Referring to FIGS. 5 to 8, another embodiment of the scroll compressor of the present invention is as follows.

[0067] In addition to the aforementioned first path section (143a) and second path section (143b), the fixed side wall section (143) may further be provided with a third path section (143i) and a communication control section (143e).

[0068] That is, the fixed side wall portion (143) may further be provided with a third path portion (143i) which is provided at the bottom of the fixed side wall portion (143) and formed to be spaced outward from the second path portion (143b); and a communication control portion (143e) which has a flow path that selectively opens and closes the second and third path portions (143b, 143i) between the first path portion (143a) and the third path portion (143i).

[0069] In this embodiment, the communication control unit (143e) is provided with a pin (143f) that moves to selectively open and close the second and third path units (143b, 143i), and an elastic member (143g) that elastically supports one side of the pin (143f).

[0070] In this embodiment, when a gap is created between the rotating scroll (150) and the fixed scroll (140), the second path section (143b), filled with high pressure, is instantaneously connected to a relatively low pressure, causing the pressure to decrease. As the pin (143f) moves in the direction of low pressure due to a pressure difference force greater than the spring force of the elastic member (143g), the second path section (143b) can be blocked, so that the first path section (143a) is connected to the third path section (143i) and can escape toward the suction pressure side of the compression chamber, thereby minimizing the reduction in volumetric efficiency.

[0071] As a result, if a gap occurs between the fixed scroll (140) and the rotating scroll (150) due to insufficient back pressure, high-pressure discharge gas can be introduced through the first path section (143a) and the third path section (143i) so that the back pressure can be automatically adjusted.

[0072] In particular, when back pressure is normally provided, the pin (143f) is elastically supported by the elastic member (143g), and when back pressure is insufficient and a gap is created between the fixed scroll (140) and the rotating scroll (150), the pin (143f) moves in a direction that compresses the elastic member (143g) due to the pressure difference between the high-pressure discharge gas and the intermediate pressure chamber, thereby blocking the second path section (143b) and opening the third path section (143i).

[0073] Accordingly, the high-pressure discharge refrigerant flows into the intermediate pressure chamber along the first path section (143a) and the third path section (143i), and the sealing force can be restored.

[0074] The restored sealing force refers to the force that causes the rotating scroll (150) to be pushed upward as high-pressure discharge gas is partially introduced into the first back pressure chamber (1312) (intermediate pressure chamber), thereby sealing the side of the rotating scroll (150) and the lower end of the fixed side wall (143) of the fixed scroll (140) to seal each other.

[0075] In this embodiment, the fixed side wall portion (143) further comprises a third path portion (143i) and a communication control portion (143e), and as a pin (143f) is installed in the communication control portion (143e) to be supported by an elastic member (143g), the high-pressure discharge refrigerant is able to flow to the first back pressure chamber (1312) through the third path portion (143i) without flowing into the suction pressure side within the compression chamber, as the pin (143f) blocks the second path portion (143b).

[0076] The communication control section (143e) may be formed in a direction that intersects the first path section (143a), the second path section (143b), and the third path section (143i).

[0077] The communication control section (143e) can be formed radially at the bottom of the fixed side wall section (143) of the fixed scroll (140).

[0078] A stopper (143h) that restricts the movement of the pin (143f) may be installed on one side of the communication control section (143e). Additionally, the communication control section (143e) is formed to accommodate the pin (143f) and the elastic member (143g) so that they can be installed. The pin (143f) may be arranged within the communication control section (143e) to block the second path section (143b) or the third path section (143i) while being elastically supported by the elastic member (143g).

[0079] The fixed scroll (140) is provided with a fixed flange portion extending radially from the bottom of the fixed side wall portion (143), and the communication control portion (143e) may be formed such that one side penetrates the outside of the fixed flange portion and the other side overlaps radially with the side of the pivoting scroll (150).

[0080] Additionally, a stopper (143h) is provided on one side of the above communication control part (143e), and the pin (143f) can be positioned to block the third path part (143i) while in contact with and supported by the stopper (143h).

[0081] The overall configuration of the scroll compressor (100) of the present invention is described with reference to FIG. 1 and others.

[0082] The casing (110) can accommodate a rotating scroll (150), a fixed scroll (140), and a main frame (130) inside.

[0083] The casing (110) is configured to have a sealed internal space. The casing (110) may be formed in a cylindrical shape, for example.

[0084] The casing (110) may include a cylindrical shell (111), an upper cap (112), and a lower cap (113).

[0085] The cylindrical shell (111) has a cylindrical shape with open upper and lower ends, and the aforementioned drive motor (120) and main frame (130) can be inserted and fixed into the inner surface. A refrigerant suction pipe (115) can be inserted and connected through the upper half of the cylindrical shell (111), for example, the upper side of the drive motor (120).

[0086] The upper cap (112) can be joined to cover the open upper end of the cylindrical shell (111), and the lower cap (113) can be joined to cover the open lower end of the cylindrical shell (111). Accordingly, the internal space of the casing (110) can be sealed.

[0087] A discharge cover (114) can be inserted into and coupled to the upper cap (112). In other words, the outer side of the discharge cover (114) is coupled to the upper cap (112), and the inner side of the discharge cover (114) can be fastened by being in close contact with the outer side of the side wall of the fixed scroll (140). Accordingly, the internal space of the casing (110) can be separated into a low-pressure section (110a) forming a suction space and a high-pressure section (110b) forming a discharge space, centered around the discharge cover (114).

[0088] A refrigerant suction pipe (115) can be formed through the middle of the cylindrical shell (111) and a refrigerant discharge pipe (116) can be formed through the upper cap (112). Accordingly, the refrigerant suction pipe (115) can be connected to the low-pressure portion (110a) of the casing (110) forming the suction space, and the refrigerant discharge pipe (116) can be connected to the high-pressure portion (110b) of the casing (110) forming the discharge space.

[0089] The scroll compressor (100) of the present invention may further include a drive motor (120).

[0090] The drive motor (120) can be installed inside the casing (110).

[0091] The drive motor (120) may include a stator (121) and a rotor (122).

[0092] The stator (121) can be installed to be fixed to the inner circumference of the casing (110) by shrink fitting, and the rotor (122) is rotatably positioned inside the stator (121).

[0093] The stator (121) may include a stator core (1211) and a stator coil (1212).

[0094] The stator core (1211) is formed in a cylindrical shape and is fixed to the inner surface of the cylindrical shell (111) by hot press fitting. The stator coil (1212) is wound on the stator core (1211) and can be electrically connected to an external power source through a terminal (not shown) that is coupled through the casing (110).

[0095] The rotor (122) may include a rotor core (1221) and a permanent magnet (1222).

[0096] The rotor core (1221) is formed in a cylindrical shape and can be rotatably inserted into the stator core (1211) at a predetermined gap. The permanent magnet (1222) can be embedded in the rotor core (1222) at a predetermined gap along the circumferential direction.

[0097] The scroll compressor (100) of the present invention may further include a rotating shaft (125).

[0098] Additionally, a rotating shaft (125) can be press-fitted and coupled to the center of the rotor core (1221). An eccentric portion (1251) is provided at the top of the rotating shaft (125) so that a pivoting scroll (150), to be described later, can be coupled eccentrically. Accordingly, the rotational force of the drive motor (120) can be transmitted to the pivoting scroll (150) through the rotating shaft (125).

[0099] Additionally, an oil passage (1252) is formed by penetrating the interior of the rotating shaft (125) in the axial direction, and an oil pickup (126) for sucking up oil stored in the lower part of the casing (110) may be provided at the bottom of the rotating shaft (125) so as to be in communication with the oil passage (1252). Accordingly, the oil stored in the oil storage space (110c) of the casing (110) is pumped by the oil pickup and sucked up through the oil passage (1252), thereby lubricating the sliding surface.

[0100] Referring to FIGS. 1 and 2, the main frame (130) according to the present embodiment may include a main flange portion (131) and an axis support protrusion (132).

[0101] The main flange portion (131) can be fixed in close contact with the inner surface of the cylindrical shell (111). In this case, at least one oil recovery passage (not shown) spaced apart from the inner surface of the cylindrical shell (111) can be formed on the outer surface of the main flange portion (131). Accordingly, oil supplied between the main frame (130) and the rotating scroll (150) can be recovered into the oil storage space (110c) of the casing (110) through the oil recovery passage (not shown).

[0102] Additionally, a scroll fixing surface (1311) may be formed on one side of the main flange portion (131), that is, on the edge of the upper surface facing the fixed scroll (140).

[0103] A thrust support surface (1313) may be formed on the upper side near the center of the main flange portion (131). Since the thrust support surface (1313) supports the pivoting scroll in the axial direction, it may be a scroll support portion (1313).

[0104] The lower part of the second path section (143b) can be positioned between the scroll support section and the scroll fixing surface.

[0105] Additionally, the lower portion of the third path section (143i) can be positioned between the outer circumference of the pivot scroll (150) and the scroll fixing surface.

[0106] A first back pressure chamber (1312) may be provided between the scroll fixing surface (1311) and the thrust support surface (1313).

[0107] The first back pressure chamber (1312) can be provided on the upper part of the main frame (130).

[0108] The first back pressure chamber (1312) can be formed to be concave between the scroll fixing surface (1311) and the thrust support surface (1313).

[0109] The first back pressure chamber (1312) may accommodate a portion of the gas discharged from the compression chamber (V). To this end, a back pressure passage may be included that communicates between the compression chamber (V) and the first back pressure chamber (1312). The back pressure passage may be formed in the pivot plate section (151) to penetrate between the compression chamber (V) and the first back pressure chamber (1312).

[0110] The first back pressure chamber (1312) can be understood as an intermediate back pressure chamber.

[0111] The first back pressure chamber (1312) can be understood as a space provided between the upper part of the main frame (130), the side of the pivoting scroll (150), and the bottom of the fixed scroll (140).

[0112] In the present invention, a first path section (143a) and a second path section (143b) are provided in the fixed scroll (140) to be connected to the first back pressure chamber (1312), so that when leakage occurs between the lower end of the side wall of the fixed scroll (140) and the side of the rotating scroll (150), high pressure is introduced into the first back pressure chamber (1312) through the first path section (143a) and the second path section (143b) so that the sealing force can be restored.

[0113] Meanwhile, referring to FIG. 2, a second back pressure chamber (1314) may be provided on the thrust support surface (1313) to accommodate back pressure gas that is relatively higher than the back pressure of the first back pressure chamber (1312). The second back pressure chamber (1314) may accommodate a portion of the gas from the compression chamber (V). To this end, a back pressure communication passage may be included to communicate between the compression chamber (V) and the second back pressure chamber (1314). Although not shown in FIG. 2, the back pressure communication passage may be formed through the rotating tip plate section (151) to enable communication between the compression chamber (V) and the second back pressure chamber (1314).

[0114] The second back pressure chamber (1314) may, for example, overlap axially with the compression chamber to which the discharge port (1411) is connected.

[0115] Meanwhile, FIG. 2 shows a sealing member (1314a, 1314b) that seals between the thrust support surface (1313) and the pivot plate portion (151).

[0116] The scroll fixing surface (1311) is a part where the fixed scroll (140) is seated and fixed, and can be formed in a stepped shape that is higher than the bottom surface of the thrust support surface (1313) and the first back pressure chamber (1312) by a predetermined height. Accordingly, a stepped surface is formed between the inner surface of the scroll fixing surface (1311) and the outer surface of the first back pressure chamber (1312), and oil flowing into the first back pressure chamber (1312) and / or the thrust support surface (1313) can be stored in a certain amount inside the scroll fixing surface (1311).

[0117] Although not illustrated in the drawing, the scroll fixing surface (1311) may be formed at the same height as the thrust support surface (1313). In this case, most of the upper surface of the main flange portion (131) forms a flat plane, making it easy to form the main frame (130).

[0118] Between the scroll fixing surface (1311) and the thrust support surface (1313), an Oldham ring support surface on which an Oldham ring (170) is seated and slides may be provided. The Oldham ring support surface may be provided on one side of the first back pressure chamber (1312).

[0119] The shaft support protrusion (132) extends from the center of the main flange portion (131) toward the drive motor (120), and a shaft support hole (1321) may be formed on the inner side of the shaft support protrusion (132) by penetrating both axial sides of the main flange portion (131). Accordingly, the main frame (130) can radially support a rotating shaft (125) inserted into the shaft support hole (1321).

[0120] Referring to FIG. 1, the fixed scroll (140) according to the present embodiment can be fixed to the main frame (130) with the pivot scroll (150) in between. For example, the fixed scroll (140) may include a fixed plate portion (141), a fixed wrap (142), and a fixed side wall portion (143).

[0121] The fixed end plate (141) is formed in the shape of a disc and can be fixed laterally in the low-pressure section (110a) of the casing (110). A discharge port (1411) and a bypass hole (1412) can be formed through the center of the fixed end plate (141) in the axial direction. Accordingly, the refrigerant compressed in the compression chamber (V) can be discharged to the high-pressure section (110b), which is the discharge space, through the discharge port (1411). The refrigerant compressed in the compression chamber (V) can be discharged to the high-pressure section (110b) through the bypass hole (1412) before reaching the discharge port (1411).

[0122] The high-pressure section (110b) may be a space defined by the upper cap (112) of the casing (110) and the upper surface of the fixed scroll (140) with the discharge cover (114), as shown in FIG. 1. The discharge port (1411) may be connected to a first path section (143a) provided on the fixed side wall section (143) of the fixed scroll (140) through the high-pressure section.

[0123] As a result, the high-pressure refrigerant discharged through the discharge port (1411) can flow into the first path section (143a) (143a) and be supplied to the first back pressure chamber (1312), thereby enabling back pressure to be assisted. The refrigerant discharged through the discharge port (1411) may be a discharge pressure.

[0124] The fixed wrap (142) can extend from the lower surface of the fixed plate section (141) toward the rotating scroll (150). The fixed wrap (142) can be formed in various shapes, such as an involute. For example, the fixed wrap (142) may be formed as a logarithmic spiral or as a plurality of arc curves.

[0125] However, if the fixed wrap (142) is formed as a logarithmic spiral, the pivot wrap (152) described later must also be formed as a logarithmic spiral, so the shape of the rotation shaft insertion part (153) described later is limited, and the stroke volume can be reduced at the same wrap height and end plate width.

[0126] The fixed wrap (142) according to the present embodiment may be formed such that the wrap curve is formed by connecting a plurality of arcs with different diameters and origins. Accordingly, the wrap thickness of the fixed wrap (142) may be formed differently along the wrap formation direction.

[0127] For example, in the fixed wrap (142) according to the present embodiment, the wrap thickness of the discharge end, which is towards the center, can be formed to be thicker than the wrap thickness of the suction end, which is towards the outermost end. Accordingly, the wrap strength at the discharge end of the fixed wrap (142), which receives a relatively high gas force, can be increased to suppress damage to the fixed wrap (142). In addition, the wrap curve of the fixed wrap (142) is formed wide so that the stroke volume can be expanded at the same wrap height and end plate width. The same applies to the swivel wrap (152) to be described later.

[0128] Additionally, the fixed wrap (142) may be formed with the same wrap height along the wrap formation direction, or may be formed with different heights. In this embodiment, an example is illustrated in which the wrap height of the fixed wrap (142) differs along the wrap formation direction of the fixed wrap (142). For example, in this embodiment, a fixed step surface (1421) is formed in the middle of the fixed wrap (142), so that the wrap height of the discharge end, which is towards the center with respect to the fixed step surface (1421), is formed lower than the wrap height of the suction end, which is towards the outermost edge. Accordingly, the wrap strength at the discharge end of the fixed wrap (142), which receives a relatively high gas force, is increased, thereby suppressing damage to the fixed wrap (142).

[0129] The fixed step surface (1421) can be formed at a position where the compression chamber (V) communicates with the discharge port (1411) at the discharge start time (discharge start point) of the compression chamber (V) that starts discharge relatively earlier among the two compression chambers (V). The same applies to the pivoting step surface (1511) to be described later, which will be explained again later.

[0130] The fixed side wall portion (143) may be formed in an annular shape by extending axially from the edge of the compression surface of the fixed end plate portion (141) to surround the fixed wrap (142). One side of the fixed side wall portion (143) facing the main frame (130) may be placed on and fastened to the scroll support surface (1311) of the main frame (130). Accordingly, the fixed scroll (140) may be supported axially on the main frame (130) and fixed axially.

[0131] The fixed side wall portion (143) is provided with a first path portion (143a) and a second path portion (143b).

[0132] The first path section (143a) is provided with a flow path through which high pressure discharged inside can flow, and is extended by a predetermined distance from the top.

[0133] As illustrated in FIGS. 2 and 3, the first path section (143a) may be formed in the axial direction (i.e., vertical direction) at the fixed side wall section (143). Additionally, the end of the first path section (143a) may be spaced radially apart from the discharge port (1411).

[0134] The second path section (143b) is provided at the bottom of the fixed side wall section (143) and is provided to face the side of the rotating scroll (150).

[0135] Since the first path section (143a) is formed to penetrate the upper end of the fixed side wall section (143) and the second path section (143b) is formed to penetrate the lower end of the fixed side wall section (143), the high-pressure refrigerant exiting the discharge port (1411) can flow from the upper end of the fixed side wall section (143) through the first path section (143a) and be supplied to the side of the rotating scroll (150) (the side of the rotating plate section (151)) through the lower end of the second path section (143b).

[0136] As a result, if a gap occurs between the fixed scroll (140) and the rotating scroll (150) due to insufficient back pressure, high-pressure discharge gas can be introduced into the gap between the contact surfaces of the fixed scroll (140) and the rotating scroll (150) so that the back pressure can be automatically adjusted.

[0137] In particular, when a gap is created between the fixed scroll (140) and the rotating scroll (150) due to the pressure difference caused by the high-pressure discharge gas and the insufficient pressure in the back pressure chamber, the high-pressure discharge gas flows into the intermediate pressure chamber, thereby restoring the sealing force.

[0138] As described above, the present invention has a thrust structure formed by the end plate of the pivoting scroll (150) and the lower side of the fixed scroll (140), and by controlling the back pressure in this end plate thrust structure.

[0139] As a result, the present invention allows back pressure and sealing force to be adjusted for various operating conditions of a scroll compressor, thereby enabling a wider operating range.

[0140] Between the first path section (143a) and the second path section (143b), an intermediate connecting section (143c) extending in a direction intersecting the first and second path sections (143b) may be further provided.

[0141] In the intermediate connecting section (143c), high-pressure refrigerant can be accommodated after passing through the first path section (143a) and before being supplied to the second path section (143b). Accordingly, when a gap is formed between the lower side wall of the fixed scroll (140) and the side of the rotating plate section (151) due to a weak sealing force, the amount of high-pressure refrigerant supplied to the first back pressure chamber (1312) (intermediate pressure) can be increased.

[0142] The second path section (143b) may be formed radially inward from the first path section (143a).

[0143] As a result, when the sealing force is sufficient, the second path section (143b) is blocked on the side of the rotating plate section (151), thereby blocking the supply of high pressure to the first back pressure chamber (1312). On the other hand, when the sealing force is insufficient and a gap is formed between the fixed scroll (140) and the rotating scroll (150), the high-pressure refrigerant that escapes through the gap via the second path section (143b) can be supplied to the first back pressure chamber (1312).

[0144] In other words, variable back pressure according to operating conditions is possible, which minimizes losses at the efficiency point and expands the operating range of the scroll compressor.

[0145] A first back pressure chamber (1312) may be provided at the top of the main frame (130).

[0146] Referring to FIG. 1, the pivot scroll (150) according to the present embodiment may be coupled to the eccentric portion (1251) of the rotation axis (125) and provided between the main frame (130) and the fixed scroll (140). Specifically, the pivot scroll (150) may include a pivot plate portion (151) and a pivot wrap (152).

[0147] The pivot plate section (151) is positioned between the main frame (130) and the fixed scroll (140) and is configured to be pivotable relative to the main frame (130) and the fixed scroll (140).

[0148] In the rotating plate section (151), a rotating wrap can be extended in a direction toward the fixed scroll (140).

[0149] The lower end of the second path section (143b) may be positioned to overlap with the side of the pivoting plate section (151). For example, the lower end of the second path section (143b) may be positioned to overlap with the outer side of the pivoting plate section (151).

[0150] As the lower end of the second path section (143b) is positioned to overlap with the side of the rotating plate section (151), when the sealing force is sufficient, the second path section (143b) is blocked by the side of the rotating plate section (151), thereby blocking the supply of high pressure to the first back pressure chamber (1312), whereas when the sealing force is insufficient and a gap is formed between the fixed scroll (140) and the rotating scroll (150), the high-pressure refrigerant that escapes through the second path section (143b) through the gap can be supplied to the first back pressure chamber (1312).

[0151] The pivot plate section (151) is formed in a roughly circular shape and can be received inside the scroll support surface (1311) of the main frame (130). A key groove (not shown) into which a key (not shown) of the Oldham ring (170) is inserted can be formed on the edge of one side of the pivot plate section (151), that is, on the lower surface (back side) facing the main frame (130). Accordingly, the pivot plate section (151) can rotate inside the scroll support surface (1311) by means of the Oldham ring (170).

[0152] The upper surface (compression surface) of the pivot plate section (151) may be formed at a uniform height or partially at a different height. For example, if the pivot shaft insertion section (153) of the pivot plate section (151) extends only toward the main frame (130) from the rear surface of the pivot plate section (151) facing the main frame (130), the entire pivot plate section (151) may be formed at a uniform height. However, if the pivot shaft insertion section (153) is formed to penetrate the pivot plate section (151) and overlap radially with the pivot wrap (152) to be described later, the height of the pivot plate section (151) may be partially, that is, higher in the part where the pivot shaft insertion section (153) is formed. In this embodiment, an example is illustrated in which the height of the pivot plate section (151) at the center is formed higher than the height at the edge. Accordingly, the upper surface (compression surface) of the rotating plate section (151) can be formed such that the discharge side height is higher than the suction side height, centered on the rotating step surface (1511). Through this, the rotation shaft insertion section (153), which will be described later, protrudes in a direction toward the fixed plate section (141), thereby shortening the distance between the first point of application where rotational force acts on the rotating scroll (150) and the second point of application where compressive force acts, and thus reducing the overturning moment of the rotating scroll (150).

[0153] The pivoting step surface (1511) connects the outer surface at the discharge end of the pivoting wrap (152) and the inner surface of the pivoting wrap (152) facing it in a radial direction, and, as with the fixed step surface (1421) mentioned earlier, can be formed at a position where the corresponding pivoting chamber (V) communicates with the discharge port (1411) at the discharge start time (discharge start point) of the pivoting chamber (V) adjacent to the discharge port (1411) among the two pivoting chambers (V).

[0154] In other words, as the discharge port (1411) is formed as an elongated irregular ellipse, at the point where the rotating step surface (1511) and the fixed step surface (1421) are separated, one end of the rotating step surface (1511) (specifically, the outer side of the rotating wrap) can be formed to be connected to a part of the discharge port (1411) or overlap in the axial direction. Accordingly, at the moment when the rotating step surface (1511) is separated from the fixed step surface (1421) during the rotational movement of the rotating scroll (150), both compression chambers (V) are connected to each other, and at the same time, one compression chamber (V) is connected to the discharge port (1411). Then, even if both compression chambers (V) are connected, the refrigerant in both compression chambers (V) moves to the discharge port (1411) and is discharged together, thereby suppressing compression loss in both compression chambers (V).

[0155] The pivoting wrap (152) can be extended toward the fixed scroll (140) from the upper surface (compression surface) of the pivoting plate section (151). Accordingly, the pivoting wrap (152) can be engaged with the fixed wrap (142) to form two pairs of compression chambers (V).

[0156] The pivoting wrap (152) can be formed in various shapes, such as an involute, to correspond to the fixed wrap (142). For example, the pivoting wrap (152) may be formed as a logarithmic spiral or as a plurality of arc curves.

[0157] However, as previously explained in the fixed wrap (142), when the pivot wrap (152) is formed as a logarithmic spiral, not only is the shape of the rotation shaft insertion part (153) limited, but the stroke volume can also be reduced at the same wrap height and end plate width. Accordingly, the pivot wrap (152) according to the present embodiment can be formed such that the wrap curve is formed by connecting multiple arcs with different diameters and origins, similar to the fixed wrap (142). Accordingly, the pivot wrap (152) can be formed such that the wrap thickness varies along the wrap formation direction, similar to the fixed wrap (142).

[0158] For example, in the present embodiment, the wrapping thickness of the discharge end, which is towards the center, of the swirling wrap (152) may be formed to be thicker than the wrapping thickness of the suction end, which is towards the outermost end. Accordingly, the wrapping strength at the discharge end of the swirling wrap (152), which receives a relatively high gas force, can be increased to suppress damage to the swirling wrap (152). In addition, the wrapping curve of the fixed wrap (142) is formed wide so that the stroke volume can be expanded at the same wrapping height and end plate width.

[0159] The swivel wrap (152) may be formed with the same wrap height along the wrap formation direction, or may be formed with different heights. In this embodiment, an example is shown where the wrap height of the swivel wrap (152) is different along the wrap formation direction. For example, according to this embodiment, the wrap height of the swivel wrap (152) may be formed such that the wrap height of the discharge end, which is towards the center with respect to the swivel step surface (1511), is lower than the wrap height of the suction end, which is towards the outermost edge. Accordingly, the wrap strength at the discharge end of the swivel wrap (152), which receives a relatively high gas force, is increased, thereby suppressing damage to the fixed wrap (142).

[0160] The rotating scroll (150) may further include a rotation axis insertion part (153).

[0161] The rotation shaft insertion part (153) is a part to which the eccentric part (1251) of the rotation shaft (125) is coupled. It is formed in a cylindrical shape and may be equipped with an eccentric bearing made of a bushing bearing on its inner surface. For convenience, the bushing bearing is defined as the inner surface of the rotation shaft insertion part (153) in the following description. Accordingly, the inner surface of the rotation shaft insertion part (153) can be understood as substantially referring to the inner surface of the bushing bearing.

[0162] The rotational shaft insertion part (153) may be formed to be located inside the pivoting wrap (152). For example, the inner surface of the rotational shaft insertion part (153) may be formed at a position that overlaps with the discharge end of the pivoting wrap (152) when projected in the axial direction. In other words, the outer surface of the rotational shaft insertion part (153) may be formed to be located on the same circle as the virtual circle connecting the outer surface at the discharge end of the pivoting wrap (152). Accordingly, the inner surface around the discharge end of the pivoting wrap (152) is located inside the outer surface of the rotational shaft insertion part (153) as previously described, that is, at the front end surface (not indicated) of the rotational shaft insertion part (153). Then, the rotational shaft insertion part (153) is formed to overlap radially with the pivot wrap (152), and the bearing area of ​​the rotational shaft insertion part (153) is secured wide to stably support the pivot scroll (150), while simultaneously forming a compression chamber (V) on the front end surface of the rotational shaft insertion part (153).

[0163] The effects of the scroll compressor according to the above embodiment are as follows.

[0164] That is, when power is applied to the drive motor (120) and rotational force is generated, the pivoting scroll (150), which is eccentrically coupled to the rotation shaft (125), pivots relative to the fixed scroll (140) by the Oldham ring (170). At this time, two pairs of compression chambers (V) that move continuously are formed between the fixed scroll (140) and the pivoting scroll (150).

[0165] Then, as the rotating scroll (150) moves from the intake port (or intake chamber) (not shown) toward the discharge port (1411) (or discharge chamber), the volume of both compression chambers (V) gradually decreases.

[0166] Then, the refrigerant is sucked into the low-pressure section (110a) of the casing (110) through the refrigerant suction pipe (115), and a portion of this refrigerant is immediately sucked into and compressed in each suction pressure chamber (not labeled) forming both compression chambers (V), while the remaining refrigerant moves toward the drive motor (120) to cool the drive motor (120) and is then sucked into the suction pressure chamber (not labeled) together with other refrigerants.

[0167] Then, this refrigerant is compressed while moving along the path of both compression chambers (V). This refrigerant is discharged from the final compression chamber (V) to the high-pressure section (110b) of the casing (110) through the discharge port (1411) of the fixed scroll (140), and this refrigerant is discharged to the outside of the compressor through the refrigerant discharge pipe (116).

[0168] When a gap occurs between the rotating scroll (150) and the fixed scroll (140) due to insufficient back pressure provided through the first back pressure chamber (1312), and leakage occurs due to insufficient axial sealing force of the compression section, high pressure passing through the first path section (143a) and the second path section (143b) is introduced into the first back pressure chamber (1312) so that the sealing force can be restored.

[0169] High-pressure oil is supplied to the first back pressure chamber (1312) through the first path section (143a) and the second path section (143b) to assist back pressure at the bottom of the rotating scroll (150), thereby reducing the gap and preventing leakage.

[0170] As described above, the present invention has a thrust structure formed by the end plate of the pivoting scroll (150) and the lower side of the fixed scroll (140), and by controlling the back pressure in this end plate thrust structure.

[0171] As a result, the present invention allows back pressure and sealing force to be adjusted for various operating conditions of a scroll compressor, thereby enabling a wider operating range.

[0172] Meanwhile, as described above, other embodiments of the present invention are described.

[0173] In addition to the aforementioned first path section (143a) and second path section (143b), the fixed side wall section (143) may further be provided with a third path section (143i) and a communication control section (143e).

[0174] That is, the fixed side wall portion (143) may further be provided with a third path portion (143i) which is provided at the bottom of the fixed side wall portion (143) and formed to be spaced outward from the second path portion (143b); and a communication control portion (143e) which has a flow path that selectively opens and closes the second and third path portions (143b, 143i) between the first path portion (143a) and the third path portion (143i).

[0175] In the above communication control unit (143e), a pin (143f) that moves to selectively open and close the second and third path units (143b, 143i) and an elastic member (143g) that elastically supports one side of the pin (143f) may be installed.

[0176] As a result, if a gap occurs between the fixed scroll (140) and the rotating scroll (150) due to insufficient back pressure, high-pressure discharge gas can be introduced into the gap between the contact surfaces of the fixed scroll (140) and the rotating scroll (150) so that the back pressure can be automatically adjusted.

[0177] In particular, when back pressure is normally provided, the pin (143f) is elastically supported by the elastic member (143g), and when back pressure is insufficient and a gap is created between the fixed scroll (140) and the rotating scroll (150), the pin (143f) moves in a direction that compresses the elastic member (143g) due to the pressure difference between the high-pressure discharge gas and the intermediate pressure chamber, thereby blocking the second path section (143b) and opening the third path section (143i).

[0178] Accordingly, the high-pressure discharge refrigerant flows into the intermediate pressure chamber along the first path section (143a) and the third path section (143i), and the sealing force can be restored.

[0179] The restored sealing force refers to the force that causes the rotating scroll (150) to be pushed upward as high-pressure discharge gas is partially introduced into the intermediate pressure chamber, thereby sealing the side of the rotating scroll (150) and the lower end of the fixed side wall (143) of the fixed scroll (140) to seal each other.

[0180] In this embodiment, the fixed side wall portion (143) further comprises a third path portion (143i) and a communication control portion (143e), and as a pin (143f) is installed in the communication control portion (143e) to be supported by an elastic member (143g), the high-pressure discharge refrigerant is able to flow to the first back pressure chamber (1312) (intermediate back pressure chamber) through the third path portion (143i) without flowing into the suction pressure side within the compression chamber, as the pin (143f) blocks the second path portion (143b).

[0181] Hereinafter, in FIGS. 5 to 8, the process of supplying high-pressure refrigerant to the first back pressure chamber (1312) through the first to third path sections (143a, 143b, 143i) is described.

[0182] Referring to FIG. 5, when the sealing force is sufficient so that no gap is created, the end of the second path section (143b) is blocked by the side of the pivoting plate section (151), and the second path section (143b) is filled with high-pressure refrigerant supplied through the first path section (143a). Additionally, FIG. 5 illustrates an example in which the fin (143f) blocks the upper end of the third path section (143i) in the initial state of the elastic member (143g).

[0183] Referring to FIG. 6, due to the reduction of intermediate pressure, a gap is created between the fixed scroll (140) and the rotating scroll (150), and as the pressure in the second path section (143b) is instantaneously lowered and communicates with the first back pressure chamber (1312), the pin (143f) moves toward the second path section (143b) in the direction of low pressure by a pressure difference force greater than the spring force of the elastic member (143g). At this time, the high-pressure refrigerant provided from the first path section (143a) flows into the third path section (143i), thereby accelerating the movement of the pin (143f) toward the second path section (143b).

[0184] Referring to FIG. 7, the first path section (143a) and the third path section (143i) are connected, so that high-pressure refrigerant flows into the first back pressure chamber (1312) which is at an intermediate pressure, and the pressure in the first back pressure chamber (1312) increases, thereby increasing the sealing force between the bottom of the fixed side wall section (143) of the fixed scroll (140) and the side of the rotating scroll (150).

[0185] Referring to FIG. 8, the gap between the bottom of the fixed side wall portion (143) of the fixed scroll (140) and the side portion of the rotating scroll (150) is eliminated, and the second path portion (143b) is blocked.

[0186] As shown in FIG. 8, the axial length of the pin (143f) is formed to be nearly equal to the axial length of the communication control part (143e), so that communication between the first path part (143a) and the second path part (143b) can be blocked. However, it is not necessarily limited to this, and the pin (143f) may be positioned to completely block the second path part (143b) itself.

[0187] The scroll compressor of the present invention allows high-pressure discharge gas to flow into the gap between the contact surfaces of the fixed scroll and the rotating scroll when a gap occurs between the fixed scroll and the rotating scroll due to insufficient back pressure, thereby enabling the back pressure to be automatically regulated.

[0188] In the scroll compressor of the present invention, when the sealing force between the fixed scroll and the rotating scroll is sufficient, the second path section is blocked on the side of the rotating end plate section, thereby blocking the supply of high pressure to the first back pressure chamber; however, when the sealing force is insufficient and a gap is formed between the fixed scroll and the rotating scroll, the high-pressure refrigerant that escapes through the gap via the second path section can be supplied to the first back pressure chamber.

[0189] In the scroll compressor of the present invention, as a pin is installed in the communication control section so as to be supported by an elastic member, the high-pressure discharge refrigerant is prevented from flowing into the suction pressure side within the compression chamber by the pin blocking the second path section, and is able to flow to the first back pressure chamber (intermediate back pressure chamber) through the third path section.

[0190] The scroll compressor of the present invention enables the performance and reliability of the compressor to be secured even in operating regions where back pressure is insufficient or behavior is unstable.

[0191] In the scroll compressor of the present invention, high-pressure refrigerant can be accommodated in the intermediate communication section after passing through the first path section and before being supplied to the second path section, so that when a gap is formed between the lower side wall of the fixed scroll and the side of the rotating plate section due to a weak sealing force, the amount of high-pressure refrigerant supplied to the first back pressure chamber (intermediate pressure) can be further increased.

[0192] The scroll compressor described above is not limited to the configuration and method of the embodiments described above; rather, the embodiments may be configured by selectively combining all or part of each embodiment so that various modifications can be made.

[0193] It is obvious to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit and essential features of the invention. Accordingly, the foregoing detailed description should not be interpreted restrictively in all respects but should be considered exemplary. The scope of the invention shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the invention are included within the scope of the invention. Explanation of the symbols

[0194] 110:Casing 114:Discharge cover 111: Cylindrical shell 112: Top cap 113: Lower cap 115: Refrigerant suction pipe 130: Mainframe 131: Main flange section 132: Axial support protrusion 1312: Back pressure chamber 143a 1st path section 143b 2nd path section 143c Intermediate connecting part 143d Shielding part 143i Third Path Section 143e Communication Control Section 143f pin 143g elastic member 143h Stopper 143: Fixed side wall section 144: Fixed flange section 145: Inner projection 1411: Discharge port 150: Turning Scroll 152: Turning Lab V: Compression chamber

Claims

Claim 1 A scroll compressor comprising: a casing; a main frame fixed inside the casing; a fixed scroll having a fixed side wall portion forming a side wall to be supported on one side of the main frame; and a rotary scroll provided between the main frame and the fixed scroll, arranged to engage with the fixed scroll, with its side portion facing the fixed side wall portion to form a compression chamber, wherein the fixed scroll has a discharge port through which high pressure compressed in the compression chamber is discharged, and the fixed side wall portion has a first path portion extending by a predetermined distance from the top, having a flow path through which high pressure discharged from the discharge port can flow inside; and a second path portion provided at the bottom of the fixed side wall portion to be communicable with the first path portion and directed toward the side portion of the rotary scroll, wherein a first back pressure chamber forming an intermediate pressure is provided at the top of the main frame, and the first back pressure chamber is communicable with the second path portion. Claim 2 A scroll compressor according to claim 1, wherein the fixed sidewall portion further comprises an intermediate connecting portion extending in a direction intersecting the first and second path portions between the first and second path portions. Claim 3 A scroll compressor according to paragraph 2, wherein the fixed scroll has a fixed flange portion extending radially from the lower end of the fixed side wall portion, and the intermediate connecting portion has one side penetrating from the outside of the fixed flange portion and the other side overlapping radially with the side of the rotating scroll, and a shielding portion installed on one side of the intermediate connecting portion. Claim 4 A scroll compressor according to claim 1, wherein the rotary scroll comprises: a rotary plate portion disposed between the main frame and the fixed scroll and configured to be rotaryly rotatable with respect to the main frame and the fixed scroll; and a rotary wrap extending from the rotary plate portion toward the fixed scroll, wherein the lower end of the second path portion is disposed to overlap with the outer side of the rotary plate portion. Claim 5 In claim 1, the main frame comprises: a main flange portion in which a rotating shaft is installed on the inner circumference; a scroll support portion provided on the inner side of the main flange portion and supporting the pivoting scroll in the axial direction; and a scroll fixing surface provided on the outer side of the main flange portion and supporting the fixed scroll in the axial direction, and the lower end of the second path portion is disposed between the scroll support portion and the scroll fixing surface, forming a scroll compressor. Claim 6 A scroll compressor according to claim 1, wherein the fixed sidewall portion further comprises: a third path portion provided at the bottom of the fixed sidewall portion and formed to be spaced outwardly from the second path portion; and a communication control portion having a flow path that selectively opens and closes the second and third path portions between the first and third path portions, wherein the communication control portion is provided with a pin that moves to enable selective opening and closing of the second and third path portions and an elastic member that elastically supports one side of the pin. Claim 7 A scroll compressor according to claim 6, wherein, in the initial state of the elastic member, the pin blocks the third path section, and in the compressed state of the elastic member, the pin blocks the second path section. Claim 8 In claim 6, the above communication control unit is a scroll compressor formed in a direction intersecting the first path unit, the second path unit, and the third path unit. Claim 9 In claim 6, the fixed scroll is provided with a fixed flange portion extending radially from the lower end of the fixed side wall portion, and the communication control portion is formed such that one side penetrates the outside of the fixed flange portion and the other side overlaps radially with the side of the rotating scroll. Claim 10 In claim 9, a stopper is provided on one side of the communication control part to restrict the movement of the pin to the outside, and the pin is arranged to block the third path part while in contact with and supported by the stopper. Claim 11 In paragraph 6, the third path section is a scroll compressor that overlaps radially with one side of the first back pressure chamber. Claim 12 In claim 6, the first path section is a scroll compressor disposed radially between the second path section and the third path section. Claim 13 In claim 1, the second path section is a scroll compressor formed radially inward from the first path section. Claim 14 In claim 6, the main frame comprises: a main flange portion in which a rotating shaft is installed on the inner circumference; a scroll support portion provided on the inner side of the main flange portion and supporting the pivoting scroll in the axial direction; and a scroll fixing surface provided on the outer side of the main flange portion and supporting the fixed scroll in the axial direction, and the lower end of the third path portion is disposed between the outer circumference of the pivoting scroll and the scroll fixing surface, thereby forming a scroll compressor.

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