Rotary compressor

Abstract

The present invention provides a rotary compressor comprising: a casing; a cylinder having a compression space within the inner peripheral surface thereof; a roller rotatably provided in the compression space of the cylinder; a drive motor including a stator and a rotor; and a first balance weight provided at one side on the upper surface of the rotor and a second balance weight provided at the other side on the lower surface of the rotor, wherein the first and second balance weights have an inner peripheral surface and an outer peripheral surface formed as a curved surface and, in the circumferential direction, the value of the ratio of the length of the inner peripheral surface of the first balance weight to the length of the outer peripheral surface thereof is less than the value of the ratio of the length of the inner peripheral surface of the second balance weight to the length of the outer peripheral surface thereof.

Description

rotary compressor

[0001] The present invention relates to a rotary compressor.

[0002] Compressors can be categorized into reciprocating compressors, rotary compressors, and scroll compressors depending on how they compress the refrigerant. A reciprocating compressor compresses fluid by forming a compression space between a piston and a cylinder and allowing the piston to reciprocate linearly. A rotary compressor compresses fluid by means of rollers that rotate eccentrically within a cylinder. A scroll compressor compresses fluid by interlocking and rotating a pair of spiral scrolls.

[0003] Among these, rotary compressors can be classified according to the way the rollers rotate relative to the cylinder. For example, rotary compressors can be classified into eccentric rotary compressors in which the rollers rotate eccentrically relative to the cylinder, and concentric rotary compressors in which the rollers rotate concentrically relative to the cylinder.

[0004] Rotary compressors can also be categorized by the way they divide the compression chamber. For example, they can be categorized into vane rotary compressors, in which vanes are in contact with rollers or cylinders to divide the compression chamber, and oval rotary compressors, in which a portion of an oval roller is in contact with a cylinder to divide the compression chamber.

[0005] The rotary compressor as described above is equipped with a drive motor, and a rotational shaft is coupled to the rotor of the drive motor, and the rotational force of the drive motor is transmitted to the roller through the rotational shaft to compress the refrigerant.

[0006] Patent Document 1 (Chinese Patent Publication No. CN106089726B) discloses a rotary compressor having a structure in which the exhaust air entry end is inclined to bring the discharge hole of the muffler closer to the axis, thereby guiding the discharged refrigerant to the vent hole, thereby inducing oil recovery to the air gap or case-stator gap, thereby reducing the amount of oil discharged.

[0007] The rotary compressor of Patent Document 1 restricts the position of the discharge hole of the muffler as well as the shape of the balance weight in order to guide the discharged refrigerant to the vent hole, but the structure of the discharge hole of the muffler is no different from the existing muffler hole, so although the structure of the balance weight can reduce the flow resistance, it has a problem in that it is difficult to perform the function of guiding it to the vent hole.

[0008] Patent Document 2 (Chinese Utility Model Publication No. CN218347575 U) discloses a rotary compressor in which the shape of the balance block is manufactured asymmetrically, one side is closer to the vent hole and the other side is farther away, and the flow of refrigerant is induced to the vent hole during rotation, thereby increasing the compressor discharge rate and reducing the oil discharge amount.

[0009] The rotary compressor of Patent Document 2 has a problem in that the balance weight itself is disadvantageous in its function because it is formed asymmetrically. In addition, the asymmetrical installation causes problems in assembly.

[0010] In a vertical rotary compressor, compressed refrigerant gas is typically ejected through the discharge port of the bearing after compression, passes through a muffler, and is ejected toward the upper part of the mechanism. The refrigerant gas exiting the muffler moves upward through the vent hole on the inside of the rotor, the air gap between the rotor and stator, and the gap in the stator.

[0011] At this time, the discharge port of the muffler is mostly located inside the outer diameter of the rotor, and the balance weight experiences resistance to rotational movement due to the discharged refrigerant gas, and the refrigerant gas is also obstructed from the discharge flow.

[0012] To solve this problem, development of a balance weight structure that reduces the resistance of the refrigerant gas is required.

[0013] In addition, development of a structure that can form a pressure difference by having different shapes of the upper and lower balance weights and guide the discharged refrigerant gas to the vent hole inside the rotor to facilitate discharge is required.

[0014] The present invention has been devised to solve the above-mentioned problem, and a first object of the present invention is to provide a rotary compressor having a structure that reduces flow resistance when refrigerant gas compressed in a compression unit flows within a casing.

[0015] A second object of the present invention is to provide a rotary compressor having a structure that can smoothly discharge refrigerant gas by forming a pressure difference in the upper and lower balance weights and guiding the discharged refrigerant gas to a vent hole inside the rotor.

[0016] A third object of the present invention is to provide a rotary compressor having a structure capable of minimizing the occurrence of resistance when the discharged air flow first hits the lower end of the second balance weight.

[0017] In order to solve the above problem, the rotary compressor of the present invention includes a casing forming an exterior; a cylinder installed inside the casing, having a compression space on an inner circumference thereof, and having a suction port connected to the compression space and capable of sucking a refrigerant; a roller rotatably provided in the compression space of the cylinder; a drive motor including a stator coupled to the inner circumference of the casing, and a rotor rotatably installed on the inner circumference of the stator and having a rotational shaft provided on the inner side; and a first balance weight installed on one side of an upper surface of the rotor, and a second balance weight installed on the other side of a lower surface of the rotor, wherein the first and second balance weights have inner and outer circumferences formed as curved surfaces, and a value obtained by dividing the length of the outer circumference of the first balance weight by the length of the outer circumference in the circumferential direction is smaller than a value obtained by dividing the length of the outer circumference of the second balance weight by the length of the inner circumference.

[0018] Due to this, when the airflow is divided by the balance weight, a pressure difference is generated so that the lower part of the rotor becomes relatively high pressure, thereby improving the flow performance of the refrigerant through the vent hole inside the rotor.

[0019] The compressor is provided with the cylinder and the roller, and has a compression unit that can discharge the compressed refrigerant sucked through the suction port in the compression space, and has a muffler provided on one side of the compression unit that has a discharge hole that can receive the compressed refrigerant and discharge it toward the rotor, and the rotor has a vent hole having a predetermined width, and an airflow branch point radius is defined outside by a predetermined distance from the inner surface of the second balance weight, and the sum of the areas of the discharge holes arranged inside the airflow branch point radius may be smaller than the sum of the cross-sectional areas of the vent holes.

[0020] Preferably, among the discharge holes, the area of ​​the discharge hole arranged inside the radius of the airflow branch point may be 50% or more of the area of ​​the discharge hole.

[0021] Due to this, the present invention can secure more than half of the muffler discharge hole area on the inside, thereby smoothly guiding airflow to the vent hole.

[0022] The above airflow branch point radius can be defined as a trace formed during one rotation of a point between the inner and outer surfaces of the second balance weight.

[0023] For example, the second balance weight may have a value of 1.5 or more, which is the length of the outer circumference divided by the length of the inner circumference in the circumferential direction.

[0024] Due to this, the refrigerant airflow on the second balance weight side can smoothly flow to the first balance weight side through the vent hole on the inside of the rotor.

[0025] The above first balance weight may have a value of 1.3 or more and 1.4 or less, which is the length of the outer circumference divided by the length of the inner circumference in the circumferential direction.

[0026] Due to this, as described above, the length of the inner circumference of the first balance weight can be made as large as possible, and conversely, the length of the second balance weight can be made as small as possible.

[0027] Accordingly, the air pressure near the second balance weight becomes greater than the air pressure near the first balance weight, so that the air pressure of the discharged gas can be smoothly guided to the vent hole inside the rotor.

[0028] The second balance weight may have an outer surface having two or more curvature values.

[0029] Therefore, the outer surface of the second balance weight can secure a longer length compared to the predetermined inner surface.

[0030] According to an example of the present invention, the second balance weight may have a rounded portion provided so that both sides of the lower portion are rounded along the upward direction in which the refrigerant flows.

[0031] This minimizes the occurrence of resistance when the exhaust airflow first hits the bottom of the second balance weight.

[0032] The above second balance weight can be formed so that the center of the radius of curvature formed by the inner surface and the center of the radius of curvature formed by the outer surface are spaced apart from each other.

[0033] The above first balance weight can be arranged so that the center of the radius of curvature formed by the inner surface and the center of the radius of curvature formed by the outer surface are spaced apart from each other.

[0034] The distance between the center of the curvature radius of the outer surface of the first balance weight and the inner surface of the first balance weight may be longer than the distance between the center of the curvature radius of the outer surface of the second balance weight and the inner surface of the second balance weight.

[0035] The distance between the center of the curvature radius formed by the inner surface of the first balance weight and the center of the curvature radius formed by the outer surface of the first balance weight may be smaller than the distance between the center of the curvature radius formed by the inner surface of the second balance weight and the center of the curvature radius formed by the outer surface of the second balance weight.

[0036] Due to this, as the rotor rotates, the speed difference that occurs when the split airflows meet simultaneously on opposite sides creates a pressure difference according to Bernoulli's principle. The pressure on the inner diameter of the second balance weight can form a relatively high pressure compared to the pressure on the inner diameter of the first balance weight, and an upward airflow is formed from the high pressure second balance weight to the low pressure first balance weight, so that the compressed discharge gas airflow can be more actively induced into the vent hole on the inner side of the rotor.

[0037] For example, the center of the radius of curvature formed by the outer surface of the first balance weight and the center of the radius of curvature formed by the outer surface of the second balance weight may be concentric with each other.

[0038] The distance between the outer surface and the inner surface of the first balance weight may be closer than the distance between the outer surface and the inner surface of the second balance weight.

[0039] The outer surface of the first balance weight may be formed with one curvature, and the inner surface of the first balance weight may be formed with a curvature that varies twice.

[0040] Due to this, the first balance weight can have a smaller ratio of the inner and outer circumferential lengths.

[0041] For example, the inner surface of the first balance weight may have a first inner curvature formed parallel to the outer surface of the first balance weight, and a second inner curvature provided between both sides of the first inner curvature and both sides of the outer surface of the first balance weight.

[0042] The inner surface of the second balance weight may be formed with one curvature, and the outer surface of the second balance weight may be formed with a curvature that can be varied twice.

[0043] Due to this, the second balance weight can have a larger ratio of inner and outer circumferential lengths.

[0044] For example, the outer surface of the second balance weight may have a first outer curved portion formed parallel to the inner surface of the second balance weight, and a second outer curved portion provided between both sides of the first outer curved portion and both sides of the inner surface of the second balance weight.

[0045] In order to solve another object of the present invention, a rotary compressor of the present invention comprises: a casing forming an exterior; a cylinder installed inside the casing, having a compression space on an inner circumference thereof, and having a suction port connected to the compression space and capable of suctioning refrigerant; a roller rotatably provided in the compression space of the cylinder; a drive motor including a stator coupled to the inner circumference of the casing, and a rotor rotatably installed on the inner circumference of the stator and having a rotational shaft provided on the inside; And it includes a first balance weight installed on one side of the upper surface of the rotor, and a second balance weight installed on the other side of the lower surface of the rotor, wherein the first and second balance weights have an inner surface and an outer surface formed as a curved surface, the first balance weight has an airflow branch point at one end on a circumference extending in a circumferential direction from the outer surface, and the second balance weight has an airflow branch point at one end provided at a point spaced radially inward by a predetermined distance from the circumference extending in a circumferential direction from the outermost outer surface.

[0046] This structure can be advantageous in generating a pressure differential so that the lower portion of the rotor becomes relatively high-pressure when airflow is divided by the balance weight. This can improve the flow performance of refrigerant through the vent hole inside the rotor.

[0047] The rotary compressor of the present invention is designed so that the upper part of the balance weight has the longest inner diameter curve and the lower part of the balance weight has the longest outer diameter curve, so that when the airflow is divided by the balance weight, a pressure difference is generated so that the lower part of the rotor becomes relatively high pressure, thereby improving the flow performance of the refrigerant through the vent hole inside the rotor.

[0048] The rotary compressor of the present invention is configured such that the ratio of the length of the outer surface of the first balance weight to the length of the inner surface is smaller than the ratio of the length of the outer surface of the second balance weight to the length of the inner surface. As a result, an upward airflow is formed from the high-pressure second balance weight to the low-pressure first balance weight, so that the compressed discharge gas flow can be more actively guided to the vent hole inside the rotor.

[0049] The rotary compressor of the present invention is provided with a rounded portion on the second balance weight, so that the occurrence of resistance can be minimized when the discharged air flow first hits the lower end of the second balance weight.

[0050] The rotary compressor of the present invention can smoothly guide airflow to the vent hole by securing more than half of the area of ​​the muffler discharge hole on the inside.

[0051] Fig. 1 is a cross-sectional view showing a rotary compressor of the present invention.

[0052] Figure 2 is a cutaway perspective view showing the first and second balance weights and at least a portion of the rotor cut away.

[0053] Figure 3 is a perspective view of Figure 2 viewed from below.

[0054] Figure 4 is a conceptual diagram showing an example in which a second balance weight is installed on a rotor.

[0055] Figure 5 is a perspective view showing the upper part of the compression section to which the muffler is coupled.

[0056] Figure 6 is a conceptual diagram showing an example in which a first balance weight is installed on a rotor.

[0057] Fig. 7 is a conceptual diagram showing an example in which a first balance weight and a second balance weight are installed on a rotor.

[0058] Fig. 8 is a side view showing an example in which a second balance weight is installed on the rotor.

[0059] Figure 9 is a perspective view showing a second balance weight.

[0060] Fig. 10 is a conceptual diagram showing an example in which a first balance weight and a second balance weight are installed on a rotor.

[0061] Hereinafter, a rotary compressor according to the present invention will be described in detail based on an embodiment illustrated in the attached drawings. In the following description, descriptions of some components may be omitted to clarify the features of the present invention.

[0062] In addition, the term "upper side" used in the following description means a direction away from a support surface supporting a rotary compressor according to an embodiment of the present invention, that is, the upper side toward the compression unit when viewed from the center of the electric motor (120) and the compression unit. The term "lower side" means a direction approaching the support surface, that is, the lower side toward the electric motor (120) when viewed from the center of the electric motor (120) and the compression unit.

[0063] Additionally, the term "axial" used in the following description refers to the longitudinal direction of the rotation axis (125). "Axial" can be understood as an up-down direction. "Radial" refers to a direction intersecting the rotation axis (125).

[0064] Fig. 1 is a cross-sectional view showing a rotary compressor of the present invention.

[0065] Hereinafter, with reference to FIG. 1, the rotary compressor of the present invention will be described.

[0066] The rotary compressor according to the present invention may be a vane rotary compressor.

[0067] The rotary compressor of the present invention comprises a casing (110) forming an exterior, a cylinder (133) installed inside the casing (110) and having a compression space (V) on an inner surface, and having a suction port connected to the compression space (V) to enable suction of refrigerant, a roller (134) rotatably provided in the compression space of the cylinder (133), a drive motor (120) including a stator (121) coupled to the inner surface of the casing (110) and a rotor (122) rotatably installed on the inner surface of the stator (121) and having a rotational shaft (125) provided on the inner side, a first balance weight (128) installed on one side of the upper surface of the rotor (122), and a second balance weight (129) installed on the other side of the lower surface of the rotor.

[0068] The first and second balance weights (128, 129) have inner and outer surfaces formed into curved surfaces.

[0069] In the circumferential direction, the value obtained by dividing the length of the outer surface (128b) of the first balance weight (128) by the length of the inner surface (128a) is provided to be smaller than the value of the ratio of the length of the outer surface (129b) of the second balance weight (129) to the length of the inner surface (129a).

[0070] This can be understood as providing a value of the ratio of the length of the inner surface (128a) and the length of the outer surface (128b) of the first balance weight (128) in the circumferential direction to be smaller than the value of the ratio of the length of the inner surface (129a) and the length of the outer surface (129b) of the second balance weight (129).

[0071] The present invention is intended to solve the problem of flow resistance of conventional refrigerant gas.

[0072] Due to the difference in the ratio of the inner and outer circumferential lengths between the first and second balance weights (128, 129), a pressure difference may be generated when the airflow is divided between the first and second balance weights (128, 129). The pressure difference may be formed to be relatively high in comparison.

[0073] Due to this, the refrigerant airflow on the second balance weight (129) side can flow to the first balance weight (128) side through the vent hole (122a) on the inside of the rotor (122).

[0074] The detailed configuration of the first and second balance weights (128, 129) will be described later, and the general configuration of the rotary compressor will be described with reference to FIG. 1.

[0075] The casing (110) is a part that forms the exterior of the compressor, and can be classified into a vertical type or a horizontal type depending on the installation method of the compressor. The vertical type has a structure in which the drive motor (120) and the compression unit (130) are arranged on both upper and lower sides along the axial direction, and the horizontal type has a structure in which the drive motor (120) and the compression unit (130) are arranged on both left and right sides. The casing (110) according to the present embodiment is described focusing on the vertical type, but it is not excluded that it can also be applied to the horizontal type.

[0076] The casing (110) may include a cylindrical intermediate shell (111), a lower shell (112) covering the lower part of the intermediate shell (111), and an upper shell (113) covering the upper part of the intermediate shell (111).

[0077] A drive motor (120) and a compression unit (130) are inserted and fixedly connected to the intermediate shell (111), and a suction pipe (115) can pass through and be directly connected to the compression unit (130). The lower shell (112) is hermetically connected to the lower end of the intermediate shell (111), and an oil storage space (110b) for storing oil to be supplied to the compression unit (130) can be formed on the lower side of the compression unit (130). The upper shell (113) is hermetically connected to the upper end of the intermediate shell (111), and an oil separation space (110c) can be formed on the upper side of the drive motor (120) to separate oil from the refrigerant discharged from the compression unit (130).

[0078] The cylinder (133) has an inner circumferential surface formed in an annular shape to form a compression space (V). In addition, the cylinder (133) has a suction port (1331), and the suction port (1331) is formed to be connected to the compression space (V) so as to suck in refrigerant and provide it to the compression space (V).

[0079] The inner surface of the cylinder (133) may be formed into an oval shape. For example, the inner surface of the cylinder (133) may be formed into an asymmetrical oval shape by combining multiple ovals.

[0080] A roller (134) is rotatably provided in a compression space (V) of a cylinder (133). In addition, a plurality of vane slots (not shown) are formed along the outer circumference of the roller (134) at preset intervals. In addition, a compression space (V) is formed between the inner circumference of the cylinder (133) and the outer circumference of the roller (134).

[0081] That is, the compression space (V) is a space formed between the inner surface of the cylinder (133) and the outer surface of the roller (134). In addition, the compression space (V) is divided into spaces equal to the number of vanes by a plurality of vanes (not shown).

[0082] The vane is configured to be slidably inserted into the vane slot and rotated together with the roller (134). In addition, a back pressure is provided at the rear end of the vane so that the front end of the vane comes into contact with the inner circumference of the cylinder (133).

[0083] The driving motor (120) can be installed in the upper internal space (110a) of the casing (110), and the compression unit (130) can be installed in the lower internal space (110a) of the casing (110), and the driving motor (120) and the compression unit (130) can be connected by a rotation shaft (125).

[0084] The drive motor (120) is a part of the electric part and provides power to drive the compression part (130). The drive motor (120) includes a stator (121), a rotor (122), and a rotation shaft (125).

[0085] The stator (121) can be fixedly installed inside the casing (110) and can be fixed by being pressed into the inner surface of the casing (110) by heat fitting or the like. For example, the stator (121) can be fixed by being pressed into the inner surface of the intermediate shell (111).

[0086] The rotor (122) is rotatably inserted into the interior of the stator (121), and a rotational shaft (125) is press-fitted and coupled to the center of the rotor (122). Accordingly, the rotational shaft (125) rotates together with the rotor (122).

[0087] The rotor (122) may be provided with vent holes (122a) formed through the upper and lower sides. The airflow of the refrigerant discharged from the compression section can flow upward through the vent holes (122a).

[0088] An oil passage can be formed in the shape of a hollow hole at the center of the rotation axis (125).

[0089] An oil pickup (not shown) may be installed in the middle or bottom of the oil passage so that oil from the oil storage space can be sucked up and supplied to the wetted part.

[0090] Additionally, the rotation shaft (125) may be formed integrally with the roller (134) or may be post-assembled by press-fitting the roller (134).

[0091] The rotation shaft (125) may have a first bearing support surface (not shown) formed between the upper half of the rotation shaft (125) with respect to the roller (134), that is, the main shaft portion pressed into the rotor (122), and the main bearing portion (123b) extending from the main shaft portion toward the roller (134), and a second bearing support surface (not shown) may be formed on the lower half of the rotation shaft (125) with respect to the roller (134), that is, the rotation shaft (125) at the lower end of the sub-bearing (132). The first bearing support surface forms a first axial support portion together with a first axial support surface (not shown) to be described later, and the second bearing support surface forms a second axial support portion together with a second axial support surface (not shown) to be described later.

[0092] The rotary compressor of the present invention may further include a main bearing (131) and a sub-bearing (132).

[0093] The main bearing (131) and the sub-bearing (132) can be installed at each end of the cylinder (133). The main bearing (131) and the sub-bearing (132) are arranged to be spaced apart from each other to form each side of the compression space (V) described above.

[0094] For example, referring to FIG. 1, an example is shown in which the main bearing (131) is installed at the top of the cylinder (133) to form the upper surface of the compression space (V), and the sub-bearing (132) is installed at the bottom of the cylinder (133) to form the lower surface of the compression space (V).

[0095] At least one of the main bearing (131) and the sub-bearing (132) may be provided with a pressure relief pocket formed concavely to communicate with the compression space (V).

[0096] Meanwhile, the rotary compressor of the present invention may be equipped with a compression unit (130).

[0097] It can be understood that the compression section (130) is formed by including a cylinder (133), a roller (134), a plurality of vanes, a main bearing (131), and a sub-bearing (132). The main bearing (131) and the sub-bearing (132) are respectively provided on the upper and lower sides of the cylinder (133) to form a compression space (V) together with the cylinder (133), the roller (134) is rotatably installed in the compression space (V), the vane is slidably inserted into the roller (134), and the plurality of vanes are each in contact with the inner circumference of the cylinder (133) so that the compression space (V) is divided into a plurality of compression chambers.

[0098] Referring to Fig. 1, the main bearing (131) can be fixedly installed in the intermediate shell (111) of the casing (110). For example, the main bearing (131) can be inserted into the intermediate shell (111) and welded.

[0099] The main bearing (131) can be tightly coupled to the upper part of the cylinder (133). Accordingly, the main bearing (131) forms the upper side of the compression space (V), supports the upper surface of the roller (134) in the axial direction, and simultaneously supports the upper half of the rotation shaft (125) in the radial direction.

[0100] The main bearing (131) may include a main plate portion (1311). The main plate portion (1311) may be coupled to the cylinder (133) to cover the upper side of the cylinder (133).

[0101] The main bearing (131) may further include a main bushing (1312).

[0102] The main bushing (1312) extends axially from the center of the main plate (1311) toward the driving motor (120) and supports the upper half of the rotation shaft (125).

[0103] The main plate portion (1311) is formed in a circular shape, and the outer surface of the main plate portion (1311) can be fixedly attached to the inner surface of the intermediate shell (111). At least one discharge port (1313) is formed in the main plate portion (1311), and a discharge valve (1315) for opening and closing the discharge port (1313) is installed on the upper surface of the main plate portion (1311), and a muffler (136) having a discharge space (not shown) to accommodate the discharge port (1313) and the discharge valve (1315) can be installed on the upper side of the main plate portion (1311).

[0104] As shown in Fig. 1, the discharge port (1313) can be formed in the main bearing (131).

[0105] However, the discharge port (1313) may be formed in the sub-bearing (132), or may be formed in each of the main bearing (131) and the sub-bearing (132), or may be formed by penetrating between the inner and outer surfaces of the cylinder (133). This embodiment will be described with reference to an example in which the discharge port (1313) is formed in the main bearing (131).

[0106] Only one discharge port (1313) may be formed. However, according to the present embodiment, multiple discharge ports (1313) may be formed at preset intervals along the compression direction (or the rotational direction of the roller (134)).

[0107] Accordingly, as in the present embodiment, the discharge port (1313) may be divided into a plurality of discharge ports (1313) and formed along the rotational direction (or compression direction) of the roller (134). In addition, the plurality of discharge ports (1313) may be formed one by one, or two may be formed as a pair.

[0108] In addition, the plurality of discharge ports (1313) can be opened and closed by the discharge valves (1315) described above. Each discharge valve (1315) can be formed as a cantilever-shaped reed valve having one end as a fixed end and the other end as a free end. Since each of these discharge valves (1315) is widely known in conventional rotary compressors, a detailed description thereof will be omitted.

[0109] The main bushing (1312) is formed in a hollow bush shape, and an oil groove in the shape of a diagonal or spiral may be formed on the inner surface of the main bushing (1312) to form a path through which oil is supplied to the wetted part.

[0110] Although not shown in the drawing, an oil groove may also be formed on the outer surface of the rotating shaft (125).

[0111] Referring to Fig. 1, the sub-bearing (132) can be tightly coupled to the lower part of the cylinder (133). Accordingly, the sub-bearing (132) forms the lower side of the compression space (V), supports the lower surface of the roller (134) in the axial direction, and simultaneously supports the lower half of the rotation shaft (125) in the radial direction.

[0112] Referring to FIG. 1, the sub-bearing (132) may include a sub-plate portion (1321). The sub-plate portion (1321) may be coupled to the cylinder (133) to cover the lower side of the cylinder (133).

[0113] Additionally, the sub-bearing (132) may further include a sub-bush portion (1322). The sub-bush portion (1322) extends axially from the center of the sub-plate portion (1321) toward the lower shell (112) to support the lower half of the rotational axis (125).

[0114] The subplate portion (1321) is formed in a disc shape, similar to the main plate portion (1311), and the outer surface of the subplate portion (1321) can be spaced apart from the inner surface of the intermediate shell (111).

[0115] The sub-bush portion (1322) is formed in a hollow bush shape, and an oil groove that provides a path for oil to flow may be provided on the inner circumferential surface of the sub-bush portion (1322).

[0116] Referring to FIG. 1, the cylinder (133) according to the present embodiment may be bolted to the main bearing (131) together with the sub-bearing (132) while being in close contact with the lower surface of the main bearing (131). As described above, since the main bearing (131) is fixedly coupled to the casing (110), the cylinder (133) may be fixedly coupled to the casing (110) by the main bearing (131).

[0117] The cylinder (133) may be formed in an annular shape with a hollow space portion to form a compression space (V) in the center. The hollow space portion is sealed by the main bearing (131) and the sub-bearing (132), thereby forming the compression space (V) described above, and a roller (134) may be rotatably coupled to the compression space (V).

[0118] Referring to Fig. 1, the cylinder (133) may be formed by having a suction port (1331) penetrate the inner and outer surfaces. However, the suction port (1331) may also be formed by penetrating the inner and outer surfaces of the main bearing (131) or the sub bearing (132).

[0119] The suction port (1331) can be formed on one circumferential side of the cylinder (133).

[0120] The inner surface of the cylinder (133) may be formed into an elliptical shape. The inner surface of the cylinder (133) according to the present embodiment may be formed into an asymmetrical elliptical shape by combining a plurality of ellipses, for example, four ellipses having different length ratios, so that they have two origins.

[0121] According to the present embodiment, the roller (134) has a circular outer surface (1341), and a rotational axis (125) may be extended as a single body or may be combined by post-assembly to the rotational center (Or) of the roller (134). Accordingly, the rotational center (Or) of the roller (134) is positioned coaxially with the axial center (not shown) of the rotational axis (125), and the roller (134) rotates together with the rotational axis (125).

[0122] However, as described above, since the inner surface of the cylinder (133) is formed in an asymmetrical elliptical shape that is biased in a specific direction, the center of rotation of the roller (134) may be arranged eccentrically with respect to the outer diameter center of the cylinder (133).

[0123] In addition, the roller (134) may have a plurality of vane slots formed along the outer circumferential surface (1341) so as to be spaced apart from each other along the circumferential direction, and a plurality of vanes, which will be described later, may be slidably inserted and coupled into each vane slot.

[0124] In a vane rotary compressor equipped with a cylinder (133), when power is applied to the drive motor (120), the rotor (122) of the drive motor (120) and the rotary shaft (125) coupled to the rotor (122) rotate, and the roller (134) coupled to or integrally formed with the rotary shaft (125) rotates together with the rotary shaft (125).

[0125] Then, the plurality of vanes are drawn out from each vane slot by the centrifugal force generated by the rotation of the roller (134) and the back pressure of the back pressure chamber supporting the rear end surface of the vane, and come into contact with the inner surface of the cylinder (133).

[0126] Then, the compression space (V) of the cylinder (133) is divided into a number of compression chambers (including suction chambers and discharge chambers, V) equal to the number of vanes by the plurality of vanes, and each compression chamber (V) moves along the rotation of the roller (134) and has a volume that varies according to the shape of the inner surface of the cylinder (133) and the eccentricity of the roller (134), and the refrigerant sucked into each compression chamber (V) is compressed while moving along the roller (134) and the vanes, and is received into the inner space of the muffler (136) through the discharge port (1313), and then exits through the discharge hole (136a) and is discharged into the inner space of the casing (110), repeating a series of processes.

[0127] At this time, the compressed refrigerant that has escaped the discharge hole (136a) of the muffler (136) flows upward through the inner surface of the second balance weight (129), flows along the vent hole (122a) on the inner side of the rotor (122), and flows to the inner surface of the first balance weight (128), and is supplied to the condenser along the refrigerant discharge pipe (113).

[0128] FIG. 2 is a cutaway perspective view showing the first and second balance weights (128, 129) and at least a portion of the rotor (122).

[0129] Fig. 3 is a perspective view of Fig. 2 viewed from below, and Fig. 4 is a conceptual diagram illustrating an example in which a second balance weight (129) is installed on a rotor (122). In addition, Fig. 5 is a perspective view illustrating the upper portion of a compression section to which a muffler (136) is coupled, and Fig. 6 is a conceptual diagram illustrating an example in which a first balance weight (128) is installed on a rotor.

[0130] Fig. 7 is a conceptual diagram showing an example in which a first balance weight (128) and a second balance weight (129) are installed on a rotor (122), Fig. 8 is a side view showing an example in which a second balance weight (129) is installed on a rotor (122), and Fig. 9 is a perspective view showing the second balance weight (129).

[0131] Fig. 10 is a conceptual diagram showing an example in which a first balance weight (128) and a second balance weight (129) are installed on a rotor (122).

[0132] Hereinafter, the first and second balance weights (128, 129) will be described in more detail with reference to FIGS. 2 to 10.

[0133] In the present invention, the balance weight (128, 129) includes first and second balance weights (128, 129).

[0134] A balance weight (128, 129) is installed on one side of at least one face of the rotor (122). The balance weight enables the rotation axis (125) to rotate eccentrically.

[0135] The first balance weight (128) is installed on one side of the upper surface of the rotor (122).

[0136] The second balance weight (129) is installed on the other side of the lower surface of the rotor (122).

[0137] The first and second balance weights (128, 129) have an inner surface (128a, 129a) and an outer surface (128b, 129b) formed as a curved surface.

[0138] The inner surface (128a, 129a) and the outer surface (128b, 129b) of the first and second balance weights (128, 129) can be divided by the airflow branch point (128c, 129c) and the airflow confluence point (128d, 129d) described later.

[0139] The first and second balance weights (128, 129) can be formed so that both sides are symmetrical with respect to a single line extending radially from the center of the rotation axis (125), so that the structure can be advantageous in resolving vibration caused by eccentric asymmetry in the compressor.

[0140] In addition, in the circumferential direction, the value obtained by dividing the length of the outer surface (128b) of the first balance weight (128) by the length of the inner surface (128a) is provided to be smaller than the value obtained by dividing the length of the outer surface (129b) of the second balance weight (129) by the length of the inner surface (129a).

[0141] This can be understood as being provided so that the value of the ratio of the length of the inner surface (128a) and the length of the outer surface (128b) of the first balance weight (128) in the circumferential direction is smaller than the value of the ratio of the length of the inner surface (129a) and the length of the outer surface (129b) of the second balance weight (129).

[0142] This causes a speed difference to occur as the split airflows meet simultaneously on opposite sides as the rotor (122) rotates. According to Bernoulli's principle, if the airflow is fast, the pressure decreases, and if the airflow is slow, the pressure increases.

[0143] Therefore, the speed difference generated by the split air flow as the rotor (122) rotates generates a pressure difference.

[0144] Since the inner diameter pressure of the second balance weight (129) is relatively high compared to the inner diameter pressure of the first balance weight (128), an upward air current is formed from the high pressure second balance weight (129) to the low pressure first balance weight (128), so that the compressed discharge gas current can be more actively guided to the vent hole (122a) inside the rotor (122).

[0145] For example, the first and second balance weights (128, 129) are preferably configured to have a smaller value, which is calculated by dividing the length of the outer surface (128b) by the length of the inner surface (128a), in the circumferential direction, based on the respective airflow branch points (128c, 129c), and the second balance weight (129) is preferably configured to have a larger value, which is calculated by dividing the length of the outer surface (129b) by the length of the inner surface (129a), in the circumferential direction.

[0146] This can be understood as the first and second balance weights (128, 129) being able to reduce the ratio of the length of the inner circumference (128a) to the length of the outer circumference (128b) of the first balance weight (128) and to increase the ratio of the length of the inner circumference (129a) to the length of the outer circumference (129b) of the second balance weight (129) based on the respective airflow branch points (128c, 129c).

[0147] In the first balance weight (128), the meaning of the ratio of the length of the inner surface (128a) to the length of the outer surface (128b) being small may mean that the length of the outer surface (128b) is small compared to the predetermined length of the inner surface (128a) (per unit length of the inner surface (128a)).

[0148] For this purpose, it is preferable that the first balance weight (128) be implemented with a structure in which the length of the inner circumference (128a) is formed as long as possible.

[0149] Meanwhile, the meaning of the ratio of the length of the inner surface (129a) to the length of the outer surface (129b) in the second balance weight (129) being large may mean that the length of the outer surface (129b) is large compared to the predetermined length of the inner surface (129a) (per unit length of the inner surface (129a)).

[0150] For this purpose, it is preferable that the second balance weight (129) be implemented with a structure in which the length of the outer circumferential surface (129b) is formed as long as possible.

[0151] Due to the difference in the ratio of the inner and outer circumferential lengths between the first and second balance weights (128, 129), a pressure difference may be generated when the airflow is divided between the first and second balance weights (128, 129). The pressure difference may be formed to be relatively high in comparison.

[0152] Due to this, the refrigerant airflow on the second balance weight (129) side can flow to the first balance weight (128) side through the vent hole (122a) on the inside of the rotor (122).

[0153] Considering the structure of the balance weight in the shape of an arc, it is impossible to make the length of the inner surface (128a, 129a) greater than the length of the outer surface (128b, 129b).

[0154] It is desirable to make the length of the inner circumference (128a, 129a) as long as possible, and to maximize the ratio of the length of the inner circumference (128a, 129a) to the outer circumference (128b, 129b). This is because the ratio of the length of the inner circumference (128a, 129a) to the outer circumference (128b, 129b) is proportional to the pressure difference.

[0155] In the present invention, the airflow branch point (128c, 129c) can be defined as a point where the airflow is divided into two airflows, i.e., the inner and outer sides of the balance weight (128, 129), by the balance weight (128, 129) as the rotor (122) rotates.

[0156] Referring to Fig. 7, the first balance weight (128) has an airflow branch point (128c) at one end on a circumference extending in the circumferential direction from the outer surface.

[0157] The second balance weight (129) is provided with an airflow branch point (129c) at one end thereof, which is provided at a point spaced radially inward by a predetermined distance from a circumference extending in the circumferential direction from the outermost outer surface.

[0158] Meanwhile, the airflow confluence points (128d, 129d) are provided on the other side opposite to the side where the airflow branch points (128c, 129c) are provided, respectively, in the first and second balance weights (128, 129).

[0159] This structure can be advantageous in generating a pressure difference so that the lower part of the rotor becomes relatively high-pressure when the airflow is divided by the balance weight. This can improve the flow performance of the refrigerant through the vent hole (122a) inside the rotor (122).

[0160] In Fig. 7, an airflow branch point (128c, 129c) is shown, which is shown as a single point where the inner surface (128a, 129a) and the outer surface (128b, 129b) of the balance weight meet.

[0161] However, the airflow branch point (128c, 129c), although expressed as a point in Fig. 7, can be understood as a single line extending in the axial direction from one end of the balance weight.

[0162] The airflow branch points (128c, 129c) may form a circular trace when the balance weight rotates once. Of course, the airflow branch points (128c, 129c) may be viewed as lines rather than points, so when the balance weight rotates once, a cylindrical trace may be formed.

[0163] The radius of the airflow branch point (128c, 129c) is the radius of the circle traced when the balance weight rotates once. Referring to Fig. 4, the radius (129f) of the airflow branch point (129c) of the second balance weight is illustrated.

[0164] Meanwhile, on the opposite side of the airflow branch point (128c, 129c), the airflow confluence point (128d, 129d) can be defined.

[0165] The airflow confluence point (128d, 129d) can be formed on the symmetrical opposite side of the airflow branch point (128c, 129c) in the balance weight.

[0166] The airflow confluence point (128d, 129d) can be understood as the point where the airflows on the inner and outer sides of the balance weight merge into one.

[0167] The airflow confluence point (128d, 129d) may be provided on the opposite side of the airflow branch point (128c, 129c), i.e., on the other end of the balance weight.

[0168] The airflow confluence point (128d, 129d), like the airflow branch point (128c, 129c), can be understood as a single line extending axially along the edge of the side portion of the balance weight.

[0169] The airflow branch point (128c, 129c) and the airflow confluence point (128d, 129d) can be partitioned to separate the inner and outer peripheries of the balance weight.

[0170] The second balance weight (129) may have a value of 1.5 or more, which is the length of the outer surface (129b) in the circumferential direction divided by the length of the outer surface (129a).

[0171] In other words, the second balance weight (129) may have a ratio of the length of the inner circumferential surface (129a) to the length of the outer circumferential surface (129b) of 1:1.5 or more.

[0172] In the second balance weight (129), the ratio of the length of the inner circumference (129a) and the length of the outer circumference (129b) in the circumferential direction can be defined between the airflow branch point (128c, 129c) and the airflow confluence point (128d, 129d).

[0173] In order to form an airflow due to a pressure difference, it is important to increase the length ratio of the second balance weight (129). In order to increase the length ratio, it may be advantageous for the airflow branch point (128c, 129c) to be closer to the inner diameter side.

[0174] The first balance weight (128) may have a value of 1.3 or more and 1.4 or less, which is the length of the outer circumference (128b) divided by the length of the inner circumference (128a) in the circumferential direction.

[0175] In other words, the ratio of the length of the inner surface (128a) and the length of the outer surface (128b) in the circumferential direction of the first balance weight (128) may be 1:1.3 or more and 1:1.4 or less.

[0176] The greater the difference in length ratio between the first balance weight (128) and the second balance weight (129), the greater the pressure difference. Due to the pressure difference between the first balance weight (128) and the second balance weight (129), the refrigerant can flow better through the vent hole (122a) inside the rotor (122).

[0177] For this purpose, it is preferable that the second balance weight (129) has a value of 1.5 or more, which is the length of the outer circumference (129b) divided by the length of the inner circumference (129a) in the circumferential direction.

[0178] In other words, it is preferable that the second balance weight (129) has a ratio of the length of the inner circumference (129a) to the length of the outer circumference (129b) of 1:1.5 or more.

[0179] Below, the first balance weight (128) and the second balance weight (129) are described in more detail.

[0180] The outer surface (128b) of the first balance weight (128) can be formed to have one radius of curvature in the circumferential direction.

[0181] The inner surface (128a) of the first balance weight (128) can be formed to have at least two radii of curvature in the circumferential direction.

[0182] Accordingly, the inner surface (128a) of the first balance weight (128) can secure a long length compared to the predetermined outer surface (128b).

[0183] That is, the outer surface (128b) of the first balance weight (128) may have a curved surface in the circumferential direction. In addition, the inner surface (128a) of the first balance weight (128) may have a curved surface in the circumferential direction.

[0184] The inner surface (128a) and outer surface (128b) of the first balance weight (128) can have curved surfaces, so that the airflow of the discharged gas can be smoothly guided to the vent hole (122a) inside the rotor (122).

[0185] As shown in FIG. 6 and FIG. 10, an example is shown in which the outer circumferential surface (128b) of the first balance weight (128) is formed with one curvature, and the inner circumferential surface (128a) of the first balance weight (128) is formed so that the curvature varies twice.

[0186] That is, the inner circumference (128a) of the first balance weight (128) may have a first inner circumferential curvature portion (128a-1) and a second inner circumferential curvature portion (128a-2).

[0187] The first inner curvature portion (128a-1) can be formed parallel to the outer circumferential surface (128b) of the first balance weight (128).

[0188] The second inner curvature portion (128a-2) may be provided between both sides of the first inner curvature portion (128a-1) and both sides of the outer surface (128b) of the first balance weight (128).

[0189] For example, the center of the curvature radius of the second inner curvature portion (128a-2) may be formed on the opposite side of the center of the curvature radius of the first inner curvature portion (128a-1) with respect to the inner circumference (128a) of the first balance weight (128). In other words, the second inner curvature portion (128a-2) is formed so that the curvature formation direction of the first inner curvature portion (128a-1) is formed outward.

[0190] Due to this, the first balance weight (128) can have a smaller ratio of the length of the inner circumference (128a) to the length of the outer circumference (128b).

[0191] The inner surface (129a) of the second balance weight (129) can be formed to have a predetermined radius of curvature in the circumferential direction.

[0192] The outer surface (129b) of the second balance weight (129) can be formed to have at least two radii of curvature.

[0193] Accordingly, the outer circumference (129b) of the second balance weight (129) can secure a long length compared to the predetermined inner circumference (129a).

[0194] That is, the inner surface (129a) of the second balance weight (129) may have a curved surface in the circumferential direction. In addition, the outer surface (129b) of the second balance weight (129) may have a curved surface in the circumferential direction.

[0195] The inner surface (129a) and outer surface (129b) of the second balance weight (129) can have curved surfaces, so that the airflow of the discharged gas can be smoothly guided to the vent hole (122a) inside the rotor (122).

[0196] As shown in FIG. 6 and FIG. 10, an example is shown in which the inner surface (129a) of the second balance weight (129) is formed with one curvature, and the outer surface (129b) of the second balance weight (129) is formed so that the curvature varies twice.

[0197] That is, the outer circumference (129b) of the second balance weight (129) may have a first outer circumference curvature portion (129b-1) and a second outer circumference curvature portion (129b-2).

[0198] The first outer circumferential curvature portion (129b-1) may be formed to be parallel to the inner circumferential surface (129a) of the second balance weight (129). The first outer circumferential curvature portion (129b-1) may be formed to have a different curvature from the inner circumferential surface (129a) of the second balance weight (129).

[0199] The second outer circumferential curvature portion (129b-2) may be provided between both sides of the first outer circumferential curvature portion (129b-1) and both sides of the inner circumferential surface (129a) of the second balance weight (129).

[0200] For example, the center of the curvature radius of the second outer circumferential curvature portion (129b-2) may be formed in the same direction as the center of the curvature radius of the second outer circumferential curvature portion (129b-2) with respect to the outer circumferential surface (129b) of the second balance weight (129). In other words, the second outer circumferential curvature portion (129b-2) is formed so that the curvature formation direction of the first outer circumferential curvature portion (129b-1) is directed inward.

[0201] Due to this, the second balance weight (129) can have a larger ratio of the length of the inner surface (129a) to the length of the outer surface (129b).

[0202] As described above, as the rotor (122) rotates, the speed difference that occurs when the split airflows meet simultaneously on opposite sides forms a pressure difference according to Bernoulli's principle. The pressure on the inner diameter of the second balance weight (129) can form a relatively high pressure compared to the pressure on the inner diameter of the first balance weight (128), and an upward airflow is formed from the high pressure second balance weight (129) to the low pressure first balance weight (128), so that the compressed discharge gas flow can be more actively induced to the vent hole (122a) on the inner side of the rotor (122).

[0203] The rotary compressor of the present invention may include a muffler (136) that receives compressed refrigerant and has a discharge hole (136a). As described above, the rotor (122) may be provided with a vent hole (122a) having a predetermined width. The sum of the areas arranged inside the radius of the airflow branch points (128c, 129c) among the discharge holes (136a) may be smaller than the sum of the areas of the vent holes (122a). Meanwhile, the radius of the airflow branch points (128c, 129c) may be defined outside by a predetermined distance from the inner surface (129a) of the second balance weight (129).

[0204] When the compressed refrigerant is discharged through the discharge hole (136a), if it is assumed that the refrigerant inside the airflow branch point (128c, 129c) rises as it is, that is, if the flow path becomes narrow, loss may occur.

[0205] Accordingly, the sum of the areas arranged inside the radius of the airflow branch point (128c, 129c) among the discharge holes (136a) is formed to be smaller than the sum of the areas of the vent holes (122a), thereby minimizing loss and enabling flow through the vent holes (122a).

[0206] Preferably, among the discharge holes (136a) of the muffler (136), the area of ​​the discharge hole (136a) positioned inside the radius of the airflow branch point (128c, 129c) may be 50% or more of the area of ​​the discharge hole (136a).

[0207] As the airflow branch point (128c, 129c) gets closer to the outer diameter (farther away from the center of rotation), the ratio of the inner circumferential length to the outer circumferential length becomes smaller, so the airflow branch point (128c, 129c) can be at an appropriate position.

[0208] In addition, by securing more than half of the area of ​​the muffler (136) discharge hole (136a) on the inside, airflow can be smoothly guided to the vent hole (122a).

[0209] As described below, the first and second balance weights (128, 129) may have different shapes.

[0210] That is, the first and second balance weights (128, 129) have different curvatures of the inner surfaces (128a, 129a), and the centers formed by the curvature radii of the inner surfaces (128a, 129a) are also different.

[0211] Additionally, the first and second balance weights (128, 129) may have different distances between the two sides of the inner surface (128a, 129a).

[0212] By this structure, it is possible to smoothly guide the airflow of the discharged gas to the vent hole (122a) inside the rotor (122).

[0213] The second balance weight (129) may be provided with a rounding portion (129e) provided so that both sides of the lower portion are rounded along the upward direction in which the refrigerant flows.

[0214] The rounding portion (129e) may be formed from the bottom in the direction of forming the inner circumference (129a). For example, the rounding portion (129e) is not provided to be rounded with the inner circumference (129a) and the outer circumference (129b). In other words, the rounding portion (129e) may be provided to be independent from the inner circumference (129a) and the outer circumference (129b).

[0215] In other words, the rounding portion (129e) may be a portion that divides the inner surface (129a) and the outer surface (129b).

[0216] Due to this, the occurrence of resistance can be minimized when the discharge airflow first hits the bottom of the second balance weight (129).

[0217] The rounding portion (129e) may be provided at at least one of the airflow branch point (128c, 129c) and the airflow confluence point (128d, 129d).

[0218] The second balance weight (129) can be formed so that the center (C2) of the radius of curvature (R2) formed by the inner surface (129a) and the center (C1) of the radius of curvature (R3) formed by the outer surface (129b) are spaced apart from each other.

[0219] Due to this, the length of the inner surface (129a) of the first balance weight (128) can be made as large as possible, and conversely, the length of the second balance weight (129) can be made as small as possible.

[0220] As shown in Fig. 10, the first balance weight (128) can be arranged so that the center (C3) of the radius of curvature (R1) formed by the inner circumferential surface (128a) and the center (C1) of the radius of curvature (R4) formed by the outer circumferential surface (128b) are spaced apart from each other.

[0221] In Fig. 10, an example is shown in which the center (C3) of the radius of curvature (R1) formed by the inner surface (128a) of the first balance weight (128) is positioned to the left of the center (C1) of the radius of curvature (R4) formed by the outer surface (128b).

[0222] The distance between the center (C1) of the radius of curvature (R4) of the outer surface (128b) of the first balance weight (128) and the inner surface (128a) of the first balance weight (128) may be longer than the distance between the center (C1) of the radius of curvature (R3) of the outer surface (129b) of the second balance weight (129) and the inner surface (129a) of the second balance weight (129).

[0223] Due to this, the first balance weight (128) can maximize the length of the inner surface (129a), and conversely, the second balance weight (129) can minimize the length. In addition, the first balance weight (128) can minimize the ratio of the length of the inner surface (128a) to the length of the outer surface (128b), and the second balance weight (129) can maximize the ratio of the length of the inner surface (129a) to the length of the outer surface (129b).

[0224] The distance between the center (C3) of the radius of curvature (R1) formed by the inner surface (128a) of the first balance weight (128) and the center (C1) of the radius of curvature (R4) formed by the outer surface (128b) of the first balance weight (128) may be smaller than the distance between the center (C2) of the radius of curvature (R2) formed by the inner surface (129a) of the second balance weight (129) and the center (C1) of the radius of curvature (R3) formed by the outer surface (129b) of the second balance weight (129).

[0225] Due to this, as described above, the length of the inner surface (128a) of the first balance weight (128) can be made as large as possible, and conversely, the length of the second balance weight (129) can be made as small as possible.

[0226] Accordingly, the air pressure near the second balance weight (129) becomes greater than the air pressure near the first balance weight (128), so that the air pressure of the discharged gas can be smoothly guided to the vent hole (122a) inside the rotor (122).

[0227] The distance between the outer circumferential surface (128a) and the inner circumferential surface (128b) of the first balance weight (128) may be closer than the distance between the outer circumferential surface (129a) and the inner circumferential surface (129b) of the second balance weight (129).

[0228] By this structure, the first balance weight (128) can maximize the length of the inner surface (129a), and conversely, the second balance weight (129) can minimize the length. In addition, the first balance weight (128) can minimize the ratio of the length of the inner surface (128a) to the length of the outer surface (128b), and the second balance weight (129) can maximize the ratio of the length of the inner surface (129a) to the length of the outer surface (129b).

[0229] Accordingly, the air pressure near the second balance weight (129) becomes greater than the air pressure near the first balance weight (128), so that the air pressure of the discharged gas can be smoothly guided to the vent hole (122a) inside the rotor (122).

[0230] The rotary compressor described above is not limited to the configuration and method of the embodiments described above, and the embodiments may be configured by selectively combining all or part of each embodiment so that various modifications can be made.

[0231] It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit and essential characteristics thereof. Therefore, the detailed description of the present invention should not be construed in any way as limiting, but rather as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present invention are intended to be included within the scope of the present invention.

[0232]

[0233] The present invention can be used in a rotary compressor.

Claims

1. Casing forming the exterior; A cylinder installed inside the casing, having a compression space on the inner surface, and having a suction port connected to the compression space to enable suction of refrigerant; A roller rotatably provided in the compression space of the cylinder; A driving motor including a stator coupled to the inner surface of the casing and a rotor rotatably installed on the inner surface of the stator and having a rotational axis provided on the inner surface; and It includes a first balance weight installed on one side of the upper surface of the rotor, and a second balance weight installed on the other side of the lower surface of the rotor, The first and second balance weights have an inner surface and an outer surface formed as a curved surface, A rotary compressor, wherein, in the circumferential direction, a value obtained by dividing the length of the outer surface of the first balance weight by the length of the inner surface is smaller than a value obtained by dividing the length of the outer surface of the second balance weight by the length of the inner surface.

2. In paragraph 1, It has the above cylinder and the above roller, and is provided with a compression unit that can discharge the compressed refrigerant sucked through the suction port from the compression space. On one side of the compression section, a muffler having a discharge hole for receiving compressed refrigerant and discharging it toward the rotor is provided; The above rotor has a vent hole having a predetermined width, The radius of the airflow branch point is defined from the outside at a predetermined distance from the inner surface of the second balance weight, A rotary compressor in which the sum of the areas arranged inside the radius of the airflow branch point among the above discharge holes is smaller than the sum of the cross-sectional areas of the vent holes.

3. In paragraph 2, A rotary compressor, wherein among the above discharge holes, the area of ​​the discharge hole arranged inside the radius of the airflow branch point is 50% or more of the area of ​​the discharge hole.

4. In paragraph 2, A rotary compressor in which the above airflow branch point radius is defined as a trace formed during one rotation of a point between the inner and outer surfaces of the second balance weight.

5. In paragraph 1, The above second balance weight is, A rotary compressor in which the length of the outer circumference divided by the length of the inner circumference is 1.5 or more.

6. In paragraph 1 or paragraph 5, The above first balance weight is a rotary compressor in which the value of the length of the outer circumference divided by the length of the inner circumference in the circumferential direction is 1.3 or more and 1.4 or less.

7. In paragraph 1, The second balance weight is a rotary compressor having an outer surface having two or more curvature values.

8. In paragraph 1, The above second balance weight is a rotary compressor having a rounded portion provided so that both sides of the lower portion are rounded along the upward direction in which the refrigerant flows.

9. In paragraph 1, The above second balance weight is a rotary compressor formed so that the center of the radius of curvature formed by the inner surface and the center of the radius of curvature formed by the outer surface are spaced apart from each other.

10. In paragraph 9, The above first balance weight is a rotary compressor in which the center of the radius of curvature formed by the inner surface and the center of the radius of curvature formed by the outer surface are spaced apart from each other.

11. In paragraph 9, A rotary compressor in which the distance between the center of the radius of curvature of the outer surface of the first balance weight and the inner surface of the first balance weight is longer than the distance between the center of the radius of curvature of the outer surface of the second balance weight and the inner surface of the second balance weight.

12. In paragraph 11, A rotary compressor in which the distance between the center of the radius of curvature formed by the inner surface of the first balance weight and the center of the radius of curvature formed by the outer surface of the first balance weight is smaller than the distance between the center of the radius of curvature formed by the inner surface of the second balance weight and the center of the radius of curvature formed by the outer surface of the second balance weight.

13. In paragraph 9, A rotary compressor in which the center of the radius of curvature formed by the outer surface of the first balance weight and the center of the radius of curvature formed by the outer surface of the second balance weight are concentric with each other.

14. In paragraph 9, A rotary compressor in which the distance between the outer surface and the inner surface of the first balance weight is shorter than the distance between the outer surface and the inner surface of the second balance weight.

15. In paragraph 1, A rotary compressor in which the outer surface of the first balance weight is formed with a single curvature, and the inner surface of the first balance weight is formed so that the curvature varies twice.

16. In paragraph 15, The inner surface of the above first balance weight is A first inner circumferential curve formed parallel to the outer circumferential surface of the first balance weight; A rotary compressor having a second inner curvature provided between both sides of the first inner curvature and both sides of the outer surface of the first balance weight.

17. In paragraph 1, A rotary compressor in which the inner surface of the second balance weight is formed with one curvature, and the outer surface of the second balance weight is formed so that the curvature varies twice.

18. In paragraph 17, The outer surface of the above second balance weight is, A first outer circumferential curvature formed parallel to the inner circumferential surface of the second balance weight; A rotary compressor having a second outer circumferential curved portion provided between both sides of the first outer circumferential curved portion and both sides of the inner circumferential surface of the second balance weight.

19. Casing forming the exterior; A cylinder installed inside the casing, having a compression space on the inner surface, and having a suction port connected to the compression space to enable suction of refrigerant; A roller rotatably provided in the compression space of the cylinder; A driving motor including a stator coupled to the inner surface of the casing and a rotor rotatably installed on the inner surface of the stator and having a rotational axis provided on the inner surface; and It includes a first balance weight installed on one side of the upper surface of the rotor, and a second balance weight installed on the other side of the lower surface of the rotor, The first and second balance weights have an inner surface and an outer surface formed as a curved surface, The above first balance weight has an airflow branch point at one end of a circle extending in the circumferential direction from the outer surface, The above second balance weight is a rotary compressor having an airflow branch point at one end thereof, which is provided at a point spaced radially inward by a predetermined distance from a circumference extending in the circumferential direction from the outermost outer surface.

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