compressor

Abstract

The present invention relates to a compressor. The present invention may comprise a casing (10) and a motor unit (MU), which is disposed inside the casing (10) and has a stator (21) and a rotor (25) that rotates a rotary shaft (30). A compression unit (CU) can be disposed inside the casing (10) at an axially spaced position along the rotary shaft (30). The present invention includes a balance weight (100) that rotates together with the rotor (25). The balance weight (100) can include: a weight body (110) coupled to the rotor (25) or the rotary shaft (30); and an inertial body (130) provided at the lower portion of the balance weight (100), facing the CU. The inertial body (130) further protrudes radially outward from the weight body (110). The inertial body (130) protrudes in the radial direction of the compressor such that the inertial moment of a rotating body can be increased without an increase in the axial height of the compressor.

Description

compressor

[0001] The present invention relates to a compressor.

[0002] Generally, a compressor refers to a mechanical device used for generating high pressure or transporting high-pressure fluids. Among these, compressors applied to refrigeration cycles, such as those in refrigerators or air conditioners, perform the function of compressing refrigerant gas and transferring it to the condenser. Depending on the method of compressing the refrigerant, these compressors can be classified into reciprocating compressors, rotary compressors, and scroll compressors.

[0003] In the above rotary compressor and scroll compressor, a part that rotates eccentrically with respect to a rotation axis can compress the refrigerant in the compression chamber. For example, in a roller eccentric rotary compressor among rotary compressors, where vanes are inserted into a cylinder to slide and contact a roller, the vanes divide the compression chamber, and the eccentric part of the rotation axis rotates in the divided compression chamber to compress the refrigerant.

[0004] At this time, since the eccentric part is connected to the outer surface of the rotating shaft and rotates eccentrically, it may cause unbalanced rotation and vibration of the rotating shaft. To solve this, a method of adding balance weights to the rotor to add inertial force to the rotating body is used in compressors such as Korean Published Patent 10-2024-0032076 (Prior Patent 1), Chinese Registered Utility Model CN ​​206611253 U (Prior Patent 2), and Chinese Registered Patent CN 106089726 B (Prior Patent 3).

[0005] The above balance weight may include an upper balance weight located on the upper side of the rotor and a lower balance weight located on the lower side of the rotor. The two balance weights can reduce vibration and noise of the compressor through appropriate design. In designing the mass and distance from the axis of rotation of the upper balance weight and the mass and distance from the axis of rotation of the lower balance weight, the sum of the centripetal forces and the sum of the moments generated in the rotating body can be made to be zero.

[0006] However, as compressors have recently become smaller, the size of rotors is also shrinking. As the rotor becomes smaller, its inertial force decreases, and the input required for low-speed operation increases, leading to a problem of reduced compressor efficiency.

[0007] To solve this, the inertial force can be compensated for by increasing the size of the upper and lower balance weights. However, even if the size of the balance weights is increased in this way, there is a limit to increasing the diameter of the balance weights due to interference with the stator. If the axial length of the balance weights is increased, the height of the compressor increases as a result, leading to a problem where the compressor cannot be miniaturized.

[0008] In addition, if one intends to increase the height of the lower balance weight, the rotor and the compression section must be separated axially to prevent axial interference between the compression section, such as the cylinder, and the lower balance weight; however, this has the disadvantage of increasing the height of the rotor and thereby causing significant vibration.

[0009] The present invention is intended to solve the problems of the prior art as described above, and the objective of the present invention is to increase the inertial force of a rotating body through a balance weight without increasing the axial height of the balance weight.

[0010] Another objective of the present invention is to increase the inertial force of a rotating body using a balance weight, regardless of whether an insulator is provided in the stator of a compressor.

[0011] Another objective of the present invention is to allow oil contained in the discharged refrigerant to be separated through a balance weight.

[0012] Another objective of the present invention is to facilitate the flow of the refrigerant discharged through the balance weight.

[0013] According to the features of the present invention for achieving the above-mentioned purpose, the present invention may include a casing and a drive unit having a rotor disposed inside the casing and rotating a stator and a rotation axis. A compression unit may be disposed inside the casing so as to be spaced apart in the axial direction of the rotation axis. The present invention includes a balance weight that rotates together with the rotor. In this case, the balance weight may include a weight body coupled to the rotor or the rotation axis and an inertia body provided at the lower part of the balance weight facing the compression unit. The inertia body protrudes further outward in the radial direction from the weight body. Since the inertia body protrudes radially from the compressor, the moment of inertia of the rotating body can be increased without increasing the axial height of the compressor.

[0014] The radial distance from the center of the rotation axis to the end of the inertial body may be greater than the radius of the rotor.

[0015] The radial distance from the center of the rotation axis to the end of the inertia body may be greater than the radius of the rotor and smaller than the radius of the stator.

[0016] The above inertial body may be positioned below the stator with respect to the above axial direction.

[0017] The above inertial body may be spaced apart in the axial direction from the lower part of the stator and the upper part of the compression part, respectively.

[0018] The end portion of the inertial body based on the above radial direction may be positioned between the stator and the compression portion based on the above axial direction.

[0019] The weight body may be extended in an arc shape along the circumferential direction of the rotor. The inertia body may be extended in an arc shape along the circumferential direction of the weight body.

[0020] The axial thickness of the inertial body may be thinner than the axial thickness of the weight body.

[0021] The weight body may be provided with a disc-shaped end plate portion coupled to the rotor. The inertia body may be spaced apart from the end plate portion in the axial direction.

[0022] The weight body may be provided with a coupling surface that is coupled to the rotor. An inclined portion may be formed on the edge of the lower surface of the weight body formed on the opposite side of the coupling surface, such that the distance from the rotation axis gradually increases toward the compression portion.

[0023] The inertia body and the inclined portion may each be provided along the edge of the lower surface. The inertia body may protrude from the outer edge of the lower surface toward the inner surface of the casing. The inclined portion may be formed on the inner edge of the lower surface toward the outer surface of the rotation axis or the outer surface of the bearing of the compression portion.

[0024] A fastening hole may be formed in the weight body to connect the balance weight to the rotor. A fastening guide wall surrounding the fastening hole may be formed in the weight body in the axial direction.

[0025] The above inclined surface can be connected to the above-mentioned fastening guide wall.

[0026] The inertia body may include a first inertia body connected to the weight body and protruding further radially outward than the weight body. In addition, the inertia body may include a second inertia body connected to the first inertia body and positioned at a location spaced further from the rotor than the first inertia body with respect to the axial direction. In this case, the radial length from the axis of rotation to the end portion of the second inertia body may be longer than the radial length from the axis of rotation to the end portion of the first inertia body.

[0027] The weight body may be arranged in a circular shape at the bottom of the rotor. A portion of the weight body positioned opposite the inertia body around the axis of rotation may be lighter in weight than the remaining portion of the weight body to which the inertia body is connected.

[0028] The stator may include a coil wound around a core and an insulator forming a winding space for the coil. In this case, the end portion of the inertia body may be positioned below the winding space with respect to the axial direction.

[0029] The insulator may include an inner insulating portion forming the inner boundary of the winding space and an outer insulating portion forming the outer boundary of the winding space. In this case, the end portion of the inertia body may be positioned between the inner insulating portion and the outer insulating portion with respect to the axial direction.

[0030] The end portion of the above-mentioned inertial body may be positioned between the inner insulating portion and the outer insulating portion with respect to the above-mentioned radial direction.

[0031] When the length of the inner insulating part protruding further in the axial direction than the rotor is denoted as H, the length of the end portion of the inertia body protruding further in the axial direction than the rotor can be 1.2H to 1.8H.

[0032] The end portion of the inertial body may be positioned below the insulator with respect to the axial direction. The end portion of the inertial body may be positioned outside the insulator with respect to the radial direction.

[0033] The insulator may include an inner insulating portion forming the inner boundary of the winding space and an outer insulating portion forming the outer boundary of the winding space. In this case, the end portion of the inertia body may be positioned between the inner insulating portion and the outer insulating portion with respect to the radial direction.

[0034] When RG1 is defined as half the difference between the inner diameter of the casing and the outer diameter of the rotor, and RG2 is defined as the difference in radial length between the end portion of the inertia body and the outer surface of the rotor, the relationship (RG1*0.7)>RG2>(RG1*0.2) can be formed.

[0035] When the difference in radial length between the end portion of the inertial body and the outer surface of the rotor is denoted as RG2, the relationship may be (RG1*0.95)>RG2>(RG1*0.2).

[0036] The balance weight may be provided with an inertia protrusion that protrudes further outward in a radial direction from the balance weight. In this case, the first surface of the inertia protrusion may face the compression portion, and the second surface of the inertia protrusion formed on the opposite side of the first surface may face the stator.

[0037] The compressor according to the present invention, as examined above, has the following effects.

[0038] The compressor of the present invention is equipped with a balance weight, and the balance weight is provided with an inertia body that protrudes further outwardly in the radial direction from the balance weight. Since this inertia body protrudes radially from the compressor, the moment of inertia of the rotating body can be increased without increasing the axial height of the compressor. Therefore, even when the compressor is miniaturized, there is an effect of reducing noise and vibration of the compressor.

[0039] Furthermore, in the compressor of the present invention, since the inertia body of the balance weight can sufficiently increase the moment of inertia of the rotating body, stable low-speed operation can be achieved without increasing the compressor input even when the compressor is operated at low speed. Accordingly, the efficiency of the compressor can be improved during low-speed operation.

[0040] In addition, the inertia body provided in the balance weight of the present invention may extend radially toward the inner surface of the casing while spaced apart from the lower portions of the rotor and stator. In this way, the inertia body can have a sufficiently large diameter in the radial direction without interfering with the transmission unit (motor). Accordingly, the effect of increasing the design freedom of the balance weight to satisfy the same moment of inertia can be obtained.

[0041] Furthermore, the inertia body provided in the balance weight of the present invention is positioned spaced downward from the electric motor, thereby avoiding interference with the electric motor. Through this structure, the present invention can be applied to both compressors equipped with an insulator on the stator of the electric motor and compressors without an insulator. Therefore, the present invention can be applied to various types of compressors, thereby improving compatibility.

[0042] In addition, the balance weight of the present invention may have an inertial body that extends radially, thereby forming a wide surface facing the compression section. As the refrigerant discharged from the compression section is scattered over the wide surface of the balance weight, the oil contained in the refrigerant can be effectively separated. Accordingly, the proportion of oil in the refrigerant discharged from the compressor can be reduced, thereby improving the efficiency of the compressor and enhancing lubrication performance.

[0043] Furthermore, in the present invention, the wide surface formed by the inertial body of the balance weight and the inclined surface of the balance weight can facilitate the flow of refrigerant discharged from the compression section. The smooth flow of refrigerant can lead to the effect of increasing the efficiency of the compressor.

[0044] In addition, the balance weight of the present invention is integrally equipped with an end plate portion, so there is no need to attach a separate end plate to the rotor. Accordingly, the effect of reducing the number of parts and assembly work of the compressor can be achieved.

[0045] FIG. 1 is a cross-sectional view showing an embodiment of a compressor according to the present invention.

[0046] FIG. 2 is a cross-sectional view showing the state in which the casing and stator constituting an embodiment of a compressor according to the present invention have been removed.

[0047] FIG. 3 is a cross-sectional view showing the structure of a compression section constituting an embodiment of a compressor according to the present invention.

[0048] FIG. 4 is a perspective view showing the structure of a rotor, a lower balance weight, and an upper balance weight constituting an embodiment of a compressor according to the present invention.

[0049] FIG. 5 is a perspective view showing the structure of an insulator and a lower balance weight constituting an embodiment of a compressor according to the present invention.

[0050] FIG. 6 is a cross-sectional view showing the structure of a motor unit and a lower balance weight constituting an embodiment of a compressor according to the present invention.

[0051] FIG. 7 is an enlarged cross-sectional view showing the structure of a motor unit and a lower balance weight constituting an embodiment of a compressor according to the present invention.

[0052] FIG. 8 is an enlarged perspective view showing a structure in which a lower balance weight is coupled to a rotor, constituting an embodiment of a compressor according to the present invention.

[0053] FIG. 9 is a perspective view showing the structure of a lower balance weight constituting an embodiment of a compressor according to the present invention.

[0054] FIG. 10 is a perspective view showing the structure of a lower balance weight constituting an embodiment of a compressor according to the present invention from an angle different from FIG. 9.

[0055] FIG. 11 is a graph comparing the cooling power / input / current of an embodiment of the compressor according to the present invention with that of a conventional compressor.

[0056] FIG. 12 is a graph comparing the noise / vibration of an embodiment of the compressor according to the present invention with that of a conventional compressor.

[0057] FIG. 13 is an enlarged cross-sectional view showing the interior of a compressor to which a second embodiment of the lower balance weight constituting the present invention is applied.

[0058] FIG. 14 is an enlarged cross-sectional view showing the interior of a compressor to which a third embodiment of the lower balance weight constituting the present invention is applied.

[0059] FIG. 15 is a cross-sectional view showing the interior of a compressor to which a fourth embodiment of the lower balance weight constituting the present invention is applied.

[0060] FIG. 16 is a perspective view showing a fifth embodiment of a lower balance weight constituting the present invention coupled to a rotor.

[0061] FIG. 17 is a perspective view showing the structure of a fifth embodiment of a lower balance weight constituting the present invention.

[0062] FIG. 18 is a perspective view showing a sixth embodiment of a lower balance weight constituting the present invention coupled to a rotor.

[0063] FIG. 19 is a perspective view showing the structure of a sixth embodiment of a lower balance weight constituting the present invention.

[0064] FIG. 20 is a perspective view showing a seventh embodiment of a lower balance weight constituting the present invention coupled to a rotor.

[0065] FIG. 21 is a perspective view showing the structure of a seventh embodiment of a lower balance weight constituting the present invention.

[0066] FIG. 22 is a side view showing the structure of the eighth embodiment of the lower balance weight constituting the present invention.

[0067] FIG. 23 is a side view showing the structure of a ninth embodiment of a lower balance weight constituting the present invention.

[0068] Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the embodiments of the present invention, if it is determined that a detailed description of related known components or functions would hinder understanding of the embodiments of the present invention, such detailed description is omitted.

[0069] A compressor according to an embodiment of the present invention may include a casing (10), a motor unit (MU), a rotating shaft (30), and a compression unit (CU). The main bearing (40), sub-bearing (50), and cylinder (60) constituting the compression unit (CU) may be stacked together. Hereinafter, a compressor in which the compression unit (CU) is positioned below the motor unit (MU) will be described as an example.

[0070] For reference, the axial direction below refers to the extension direction of the rotation axis (30). In FIG. 1, the reference numeral X represents a virtual extension line extending the center of the rotation axis (30) in the axial direction. The radial direction of the rotation axis (30) is a direction perpendicular to the axial direction. In FIG. 1, arrow U indicates the upward direction relative to the axial direction, and arrow D indicates the downward direction relative to the axial direction. Arrow R indicates the radial direction perpendicular to the axial direction.

[0071] The above casing (10) can form the exterior of the compressor. The above casing (10) is a part that forms the exterior of the compressor and can be classified into a vertical or horizontal type depending on the installation form of the compressor. A vertical casing is a structure in which the electric motor (MU) and the compressor (CU) are arranged on both the upper and lower sides along the axial direction, and a horizontal casing is a structure in which the electric motor (MU) and the compressor (CU) are arranged on both the left and right sides. The casing (10) according to the present embodiment is described as an example of a vertical casing (10).

[0072] The above casing (10) may consist of a cylindrical body shell (11) that is open at the top and bottom. The upper part of the body shell (11) of the casing (10) that is open may be closed by an upper shell (12). A discharge space (DS) into which compressed refrigerant is introduced may be formed at the bottom of the upper shell (12). The part of the body shell (11) that is open downward may be closed by a lower shell (13). The body shell (11) may also be viewed as an intermediate shell.

[0073] The electric motor (MU) and the compressor (CU) can be fixed inside the body shell (11). The body shell (11) may be provided with a suction pipe (IP). The suction pipe (IP) forms an inlet for sucking in refrigerant. The suction pipe (IP) can be directly connected to the compressor (CU). This structure will be explained again below.

[0074] The upper shell (12) may be provided with a discharge pipe (14) for discharging refrigerant to the outside. The discharge pipe (14) may be connected to a pipe (not shown) that delivers refrigerant to a condenser (not shown) of a refrigeration cycle.

[0075] A cluster (15) for transmitting external power to the motor unit (MU) may be disposed in the upper shell (12). The cluster (15) can be viewed as a type of connector. When an external connector (not shown) is connected to the cluster (15), external power can be transmitted to the motor unit (MU) through a wire (not shown). As another example, the cluster (15) may be disposed in the body shell (11) instead of the upper shell (12). Reference numeral 17 indicates a support plate that supports the compressor.

[0076] An electric motor (MU) may be disposed inside the casing (10). The electric motor (MU) generates rotational force and can rotate the rotation shaft (30). In this embodiment, the electric motor (MU) is disposed relatively above the compression unit (CU) with respect to the axial direction, but conversely, the compression unit (CU) may be disposed above the electric motor (MU). The electric motor (MU) may be largely composed of a stator (21) and a rotor (25).

[0077] The stator (21) constituting the above-mentioned electric motor (MU) may include a stator core (22) and a coil (23). The stator (21) is formed in a cylindrical shape and may be fixed to the inner surface (11a) of the body shell (11) by hot press fitting. The coil (23) is wound on the stator core (22) and may be electrically connected to an external power source through the cluster (15) which is coupled through the body shell (11). For reference, in FIG. 4, reference numeral 21A shows the outer surface of the stator (21).

[0078] The stator (21) may include an insulator (24, see FIG. 5). The insulator (24) may have a roughly annular structure. The insulator (24) may be coupled to the stator core (22). The insulator (24) may provide a space where the coil (23) is wound. The insulator (24) may be made of an insulating material such as synthetic resin. The insulator (24) may be provided at the bottom and top of the stator (21), respectively.

[0079] The insulator (24) may include an inner insulating portion (24a) forming the inner boundary of the winding space (WS) and an outer insulating portion (24b) forming the outer boundary of the winding space (WS). The inner insulating portion (24a) and the outer insulating portion (24b) are spaced apart from each other in the radial direction of the stator (21), and a winding space (WS) that is relatively axially recessed may be provided between them. The coil (23) may be wound in the winding space (WS).

[0080] In this embodiment, the outer insulating portion (24b) is formed with a higher axial height than the inner insulating portion (24a). The outer insulating portion (24b) may be formed higher than the inner insulating portion (24a) so that the coil (23) wound in the winding space (WS) does not extend beyond the outer insulating portion (24b). Looking at the drawing, the outer insulating portion (24b) extends further downward than the inner insulating portion (24a).

[0081] As another example, the outer insulating part (24b) may have the same height as the inner insulating part (24a), or the height of the inner insulating part (24a) may be higher. As yet another example, the insulator (24) may be omitted. An embodiment in which the insulator (24) is omitted will be described again below.

[0082] Looking at the structure of the rotor (25), the rotor (25) may include a rotor core (26) and a permanent magnet (27). The permanent magnet (27) may be arranged in the rotor (25) to cross the rotor cores (26), which are composed of a plurality of layers, in the axial direction. End plates (28) may be provided at both ends of the rotor (25) to prevent the permanent magnet (27) from detaching. Referring to FIG. 8, the end plates (28) may be fixed to the rotor core (26) by a first fastener (B1). For reference, in FIG. 2, reference numeral 25A shows the outer surface of the rotor (25).

[0083] Balance weights (100, 170) may be provided on the upper and lower portions of the rotor (25). The balance weights (100, 170) are coupled to the rotor (25) or the rotation shaft (30) and rotate together with the rotor (25) and the rotation shaft (30). The balance weights (100, 170) can increase the moment of inertia of the rotor of the compressor. Here, the rotor refers to a part that rotates together with the rotation shaft (30), and may include the rotation shaft (30), the rotor (25), and the balance weights (100, 170). The detailed structure of the balance weights (100, 170) will be explained again below.

[0084] The above-mentioned rotational shaft (30) is rotatably supported by the main bearing (40) and the sub-bearing (50). The main bearing (40) and the sub-bearing (50) can be stacked on the upper and lower parts of the cylinder (60), respectively. The sub-bearing (50) and the cylinder (60) can be fixed inside the casing (10) through the main bearing (40). The main bearing (40) and the sub-bearing (50) are distinguished for convenience, and the main bearing (40) and the sub-bearing (50) may also be referred to as the first bearing and the second bearing, respectively. Reference numeral 52' indicates a portion of the sub-bearing (50) that extends to surround the rotational shaft.

[0085] An oil passage (34) may be formed along the axial direction of the rotation shaft (30) at the center of the rotation shaft (30). Oil is stored in an oil storage space (RS) provided on the inner bottom side of the casing (10), and the stored oil can be transferred upward through the oil passage (34) provided on the rotation shaft (30). The transferred oil can be supplied to each part to perform a lubrication function.

[0086] As shown in FIG. 1, oil passages (35a, 35b) may be formed in the middle of the oil passage (34) in the radial direction of the rotation axis (30). In this embodiment, the oil passages (35a, 35b) include a first oil passage (35a) and a second oil passage (35b). The first oil passage (35a) is connected to the electric motor (MU), and the second oil passage (35b) is connected to the main bearing (40) and the sub-bearing (50). The second oil passage (35b) is composed of two second oil passages (35b) with different heights, each connected to the main bearing (40) and the sub-bearing (50).

[0087] An oil pickup (37) may be installed in the middle or bottom of the oil passage (34). The oil pickup (37) may be a gear pump, a viscous pump, a centrifugal pump, etc. When the rotating shaft (30) rotates, the oil filled in the oil storage space (RS) of the casing (10) is pumped by the oil pickup (37), and the pumped oil rises along the oil passage (34) and is supplied to the sub-bearing (50) and main bearing (40) through the second oil passage (35b) to facilitate the rotation of the rotating shaft (30). The oil that continues to rise can also be supplied to the electric motor (MU) through the first oil passage (35a).

[0088] The above-mentioned rotating shaft (30) may be provided with an eccentric part (38). The eccentric part (38) may have a structure protruding to one side from the rotating shaft (30). The eccentric part (38) is placed in the compression space (V) of the compression unit (CU) to be described below. The eccentric part (38) is rotatably installed in the compression space (V) and can serve to compress the refrigerant in the compression space (V) through rotation. The eccentric part (38) may be integrally provided with the rotating shaft (30) or may be composed of a separate part assembled to the rotating shaft (30).

[0089] Next, looking at the compression section (CU), as shown in FIG. 2, the compression section (CU) may include a cylinder (60) positioned at the center, and a main bearing (40) and a sub-bearing (50) positioned at the upper and lower portions of the cylinder (60), respectively. In addition, the eccentric portion (38) may also be considered as part of the compression section (CU). The cylinder (60), the main bearing (40), and the sub-bearing (50) may be combined with each other to form a compression space (V) in the portions facing each other.

[0090] Any one of the main bearing (40), sub-bearing (50), or cylinder (60) may be fixedly installed in the body shell (11). In this embodiment, the cylinder (60) is fixed to the inner surface (11a) of the body shell (11). For example, the cylinder (60) may be inserted into the body shell (11) and welded.

[0091] Referring to FIG. 3, the structure of the compression space (V) constituting the compression section (CU) is such that the eccentric part (38) is disposed in the compression space (V). A separate roller (39) is coupled to the eccentric part (38) so that it can rotate together. The compression chamber (V) is equipped with a vane (70) so that the compression chamber (V) can be divided into a plurality of compression chambers (V, V') together with the roller (39). The vane (70) is slidably coupled to the cylinder (60), and one end of the vane (70) can detachably contact the outer surface of the roller (39). The other end of the vane (70) can be inserted into the back pressure pocket (66) of the cylinder (60). The back pressure pocket (66) is intended to provide back pressure to the rear end of the vane (70).

[0092] A suction path (62) connected to the suction pipe (IP) is formed in the above compression section (CU). When refrigerant flows into the compression chamber (V) through the suction path (62), the refrigerant can be compressed inside the compression chamber (V), which is narrowed by the rotation of the roller (39). The compressed refrigerant can be discharged through the main bearing (40). Referring to FIG. 2, a discharge valve (14) may be provided on the upper surface of the main bearing (40). The discharge valve (14) can serve to open and close a discharge port (not shown) formed in the main bearing (40).

[0093] The above compression unit (CU) may include a discharge muffler (90, 95). The discharge muffler (90, 95) may be positioned at least on either the upper part of the main bearing (40) or the lower part of the sub-bearing (50). In this embodiment, the discharge muffler (90, 95) includes an upper muffler (90) positioned on the upper part of the main bearing (40) and a lower muffler (95) positioned on the lower part of the sub-bearing (50).

[0094] The upper muffler (90) forms an upper space (91) that accommodates the discharge port (not shown) and the discharge valve (45, see FIG. 2) between itself and the upper surface of the main bearing (40). The lower muffler (95) forms a lower space (96) that accommodates the discharge port and the discharge valve between itself and the lower surface of the sub-bearing (50). Although not shown, compressed refrigerant may flow through the muffler discharge ports formed in the discharge mufflers (90, 95). In FIG. 2, the arrows indicate the path through which the compressed refrigerant passes through the discharge mufflers (90, 95) and is discharged.

[0095] Next, the balance weights (100, 170) will be described with reference to FIG. 4. In this embodiment, the balance weights (100, 170) include a first balance weight (100) and a second balance weight (170). The first balance weight (100) is positioned at the bottom of the rotor (25), and the second balance weight (170) is positioned at the top of the rotor (25). Accordingly, the first balance weight (100) may be referred to as the lower balance weight (170), and the second balance weight (170) as the upper balance weight (100). The first balance weight (100) and the second balance weight (170) are positioned at symmetrical positions to each other, thereby increasing the moment of inertia of the rotating body. As another example, the second balance weight (170) may be omitted. In this case, the first balance weight (100) may also be referred to as the balance weight (100).

[0096] The first balance weight (100) may be positioned at the bottom of the rotor (25). Here, the bottom of the rotor (25) refers to a position that is relatively closer to the compression section (CU) than the top of the rotor (25) with respect to the axial direction. The first balance weight (100) may be coupled to the rotor (25) at the bottom of the rotor (25) or to the rotation axis (30).

[0097] The first balance weight (100) may have a structure that surrounds the rotation axis (30) at the bottom of the rotor (25). The first balance weight (100) may have an arc shape corresponding to the shape of the bottom of the rotor (25). The first balance weight (100) may be positioned on the opposite side of the eccentric part (38). Looking at FIG. 2, the first balance weight (100) is positioned to the right of the rotation axis (30), while the eccentric part (38) protrudes to the left of the rotation axis (30). While maintaining this phase difference, the eccentric part (38) and the first balance weight (100) can rotate together with the rotation axis (30).

[0098] Referring to FIG. 4, the first belt includes a weight body (110) coupled to the rotor (25) or the rotation axis (30). The weight body (110) may be formed in the shape of a ring that is roughly cut in half. The weight body (110) may have an arc shape along the lower part of the rotor (25). The weight body (110) may extend in a roughly semicircular shape. In this embodiment, the weight body (110) is coupled to the bottom surface of the rotor (25). As another example, the weight body (110) may be coupled to the rotation axis (30).

[0099] As shown in FIG. 8, the angle between the two ends (134) of the weight body (110) passing through the center of the rotation axis (30) can be approximately 180 degrees. Here, the two ends (134) of the weight body (110) refer to the two end portions based on the circumferential direction of the rotor (25). When a virtual extension line connecting the two ends (134) of the weight body (110) passes through the center of the rotation axis (30), the central angle of the arc shape formed by the weight body (110) becomes 180 degrees. As another example, the angle between the two ends (134) of the weight body (110) passing through the center of the rotation axis (30) may be less than 180 degrees or greater than 180 degrees. For reference, in FIG. 8, the reference numeral SH indicates the shaft hole of the rotor (25) on which the rotation axis (30) is mounted. The center of the above shaft hole (SH) becomes the center of the above rotation axis (30).

[0100] Based on the above axial direction, the upper surface of the weight body (110) can form a coupling surface (111) that is in close contact with the lower surface of the rotor (25). In this state, the weight body (110) can be assembled to the rotor (25). Referring to FIG. 8, the second fastener (B2) is shown fixing the weight body (110) to the rotor (25). In FIG. 8, the coupling surface (111) of the weight body (110) is in close contact with the rotor (25) and is covered.

[0101] Referring to FIG. 5, the side (112) of the weight body (110) has a curved shape. The side (112) of the weight body (110) may face the inner insulating part (24a) constituting the insulator (24). The side (112) of the weight body (110) may be positioned at a location spaced apart from the inner insulating part (24a) toward the rotation axis (30) with respect to the radial direction. The side (112) of the weight body (110) may be spaced a predetermined distance from the inner insulating part (24a). This structure will be explained again below.

[0102] The weight body (110) may be positioned to surround the rotation axis (30). The weight body (110) may be positioned to surround the rotation axis (30) without directly contacting the rotation axis (30). To this end, an avoidance groove (113) is formed in the center of the weight body (110). The avoidance groove (113) may have a shape that is recessed radially outward from the first balance weight (100).

[0103] A weight fastening hole (115) may be formed in the weight body (110). The weight fastening hole (115) may be formed by penetrating the first balance weight (100) in the axial direction. A second fastening member (B2) is inserted into the weight fastening hole (115) to fix the first balance weight (100) to the rotor (25). A plurality of weight fastening holes (115) may be arranged in the weight body (110) so as to be spaced apart along the arc direction of the weight body (110). In this embodiment, two weight fastening holes (115) are formed in the weight body (110).

[0104] A fastening groove (116) may be formed in the weight body (110) surrounding the weight fastening hole (115). The fastening groove (116) surrounds the weight fastening hole (115) and has a recessed shape in the weight body (110). The fastening groove (116) is recessed in the axial direction. In this embodiment, the fastening groove (116) extends to the bottom surface (131) of the inertia body (130), and the fastening groove (116) is open toward the compression part (CU). The above fastening groove (116) allows the second fastening member (B2) and an assembly tool (not shown) to access the weight fastening hole (115) more easily, and the above fastening groove (116) also prevents the head portion of the second fastening member (B2) from protruding further in the axial direction than the bottom surface of the first balance weight (100), that is, the bottom surface (131) of the inertia body (130). Such an appearance is illustrated in FIG. 8.

[0105] Referring to FIGS. 9 and 10, the fastening groove (116) may be shaped such that it gradually narrows in width from the lower surface (111') of the first balance weight (100) toward the weight fastening hole (115). Accordingly, the inner wall of the fastening groove (116) may form a curved fastening guide wall (117). The fastening guide wall (117) can guide the second fastening member (B2) and the assembly tool toward the weight fastening hole (115). Since the fastening guide wall (117) faces the compression section (CU), the refrigerant discharged from the compression section (CU) can flow toward the fastening curved section. As the refrigerant flows along the curved fastening guide wall (117), vortices can be suppressed.

[0106] An inclined section (120) may be formed on the edge of the lower surface (111') of the weight body (110) formed on the opposite side of the aforementioned coupling surface (111), such that the distance from the rotation axis (30) gradually increases toward the compression section (CU). The inclined section (120) extends along the edge of the lower surface (111') and may have an inclined or curved shape. Since the inclined section (120) faces the compression section (CU), the refrigerant discharged from the compression section (CU) can flow toward the inclined section (120). The inclined section (120) can naturally guide the flow of the refrigerant toward the discharge space (DS).

[0107] The inclined portion (120) may be provided along the edge of the lower surface (111') of the first balance weight (100) together with the inertia body (130). The inclined portion (120) is formed on the inner edge of the coupling surface (111) toward the outer surface of the rotation axis (30) or the outer surface of the bearing (40, 50) of the compression portion (CU). In this embodiment, the inclined portion (120) faces the outer surface of the main bearing (40). The inertia body (130) protrudes from the outer edge of the lower surface (111') toward the inner surface (11a) of the casing (10). Consequently, the inclined portion (120) and the inertia body (130) face opposite directions.

[0108] The inclined portion (120) can be connected to the fastening groove portion (116). The fastening groove portion (116) can be formed in a shape where a part of the inclined portion (120) is recessed in the radial direction. Accordingly, the inclined portion (120) can also be connected to the fastening guide wall (117). In this way, the refrigerant discharged from the compression portion (CU) can flow along the inclined portion (120) and the fastening guide wall (117) connected to the inclined portion (120).

[0109] The first balance weight (100) further includes an inertia body (130). The inertia body (130) may be provided at the bottom of the first balance weight (100) facing the compression section (CU). The inertia body (130) protrudes further outward in a radial direction from the weight body (110). The inertia body (130) may protrude further outward in a radial direction from the bottom of the weight body (110) than the weight body (110) to increase the inertia force of the first balance weight (100). Since the inertia body (130) protrudes radially outward from the compressor, the inertia force of the rotating body can be increased without increasing the axial height of the compressor. Therefore, noise and vibration of the compressor can be reduced even when the compressor is miniaturized. The inertia body (130) may also be described as an inertia protrusion that protrudes further in a radial direction from the outer surface of the first balance weight (100).

[0110] Looking at the structure of the inertia body (130), the inertia body (130) may be provided around the edge of the weight body (110). The inertia body (130) may be provided along the lower edge of the weight body (110). Referring to FIGS. 4 and 5, the inertia body (130) protrudes from the lower end of the weight body (110) toward the opposite side of the inclined portion (120). More precisely, the inertia body (130) protrudes from the lower edge of the weight body (110) toward the radial outer side of the rotor (25). Accordingly, a step structure may be formed between the weight body (110) and the inertia body (130). In FIG. 10, reference numeral 114 indicates the step structure formed between the weight body (110) and the inertia body (130).

[0111] When the inertia body (130) protrudes from the bottom of the weight body (110), the inertia body (130) can be positioned at the location furthest from the rotor (25) in the axial direction. In this way, when the inertia body (130) is positioned at the location furthest from the rotor (25) in the axial direction, the increase in the moment of inertia caused by the inertia body (130) can be maximized.

[0112] Since the inertia body (130) is provided around the edge of the weight body (110), the inertia body (130) may have an approximately arc shape. The inertia body (130) may be provided continuously around the edge of the weight body (110). As another example, the inertia body (130) may be provided intermittently along the edge of the weight body (110). That is, a plurality of inertia bodies (130) may be provided spaced apart from each other along the edge of the weight body (110).

[0113] Referring to FIGS. 5 and 6, the axial height (H3) of the first balance weight (100) is higher than the axial height (H1) of the inner insulation part (24a). Here, the axial height (H3) of the first balance weight (100) refers to the distance the first balance weight (100) protrudes axially from the bottom surface of the rotor (25), and the axial height (H1) of the inner insulation part (24a) refers to the distance the inner insulation part (24a) protrudes axially from the bottom surface of the rotor (25). As such, if the axial height (H3) of the first balance weight (100) is higher than the axial height (H1) of the inner insulation part (24a), the bottom of the first balance weight (100) can protrude further downward from the bottom (24a') of the inner insulation part (24a), more precisely in the direction of the compression part (CU).

[0114] The axial height (H3) of the first balance weight (100) may be lower than the axial height (H2) of the outer insulation part (24b). Here, the axial height (H2) of the outer insulation part (24b) refers to the distance the outer insulation part (24b) protrudes axially from the bottom surface of the rotor (25). If the axial height (H3) of the first balance weight (100) is lower than the axial height (H2) of the outer insulation part (24b), the bottom (24b') of the outer insulation part (24b) may protrude further downward from the bottom of the first balance weight (100), more precisely in the direction of the compression part (CU).

[0115] Consequently, when viewed with respect to the axial direction, the end portion (132) of the inertia body (130) can be positioned between the end portion (24a') of the inner insulation portion (24a) and the end portion (24b') of the outer insulation portion (24b). In this way, the part protruding furthest downward with respect to the axial direction from the electric motor (MU) can be the end portion (24b') of the outer insulation portion (24b).

[0116] Meanwhile, the height (H3B) of the inertia body (130) may be lower than the height (H3A) of the weight body (110) excluding the inertia body (130). In order to secure a separation distance (HG1) from the upper muffler (90) positioned at the bottom of the first balance weight (100), the height (H3B) of the inertia body (130) may be formed lower than the height (H3A) of the weight body (110).

[0117] In this embodiment, since the inertia body (130) protrudes in the radial direction rather than the axial direction, (i) a larger moment of inertia can be formed, (ii) a sufficiently long separation distance (HG1) from the compression part (CU) can be secured, and (iii) the surface area facing the compression part (CU) can be made larger. When the surface area of ​​the first balance weight (100) facing the compression part (CU) is increased by the inertia body (130), the refrigerant discharged from the compression part (CU) is scattered over the large surface of the first balance weight (100), and the oil contained in the refrigerant can be effectively separated.

[0118] The inertia body (130) may be positioned below the stator (21) with respect to the axial direction. In this embodiment, the inertia body (130) is positioned below the coil (23) constituting the stator (21) and the inner insulation part (24a). The inertia body (130) is connected at the bottom of the weight body (110), and since the bottom of the weight body (110) is positioned below the coil (23) and the inner insulation part (24a), the inertia body (130) can protrude further toward the inner surface (11a) of the casing (10) than the rotor (25). Through this structure, the increase in the moment of inertia caused by the inertia body (130) can be made even greater.

[0119] Consequently, in this embodiment, the first surface of the inertia body (130) faces the compression section (CU), and the second surface of the inertia body (130), formed on the opposite side of the first surface, faces the stator (21). Here, the first surface becomes the bottom surface (131) of the inertia body (130), and the second surface becomes the top surface (131') of the inertia body (130).

[0120] The upper surface (131') of the inertia body (130) and the insulator (24) may be separated from each other in the axial direction. More precisely, as shown in FIG. 6, the upper surface (131') of the inertia body (130) and the inner insulating part (24a) may be separated from each other by a predetermined distance (HG2) in the axial direction. Accordingly, the inertia body (130) can be rotated without interference with the inner insulating part (24a).

[0121] Referring to FIG. 6, the length of the inner insulating portion (24a) protruding further in the axial direction than the rotor (25) is indicated as H1. The end portion (132) of the inertia body (130) also protrudes further in the axial direction than the rotor (25). At this time, the length of the end portion (132) of the inertia body (130) protruding further in the axial direction than the rotor (25) is HG2 + H3B. That is, the sum of the distance (HG2) of the upper surface (131') of the inertia body (130) separated from the inner insulating portion (24a) in the axial direction and the axial thickness (H3B) of the inertia body (130) becomes the length of the end portion (132) of the inertia body (130) protruding further in the axial direction than the rotor (25).

[0122] At this time, it is preferable that the length (HG2+H3B) of the end portion (132) of the inertia body (130) protruding further in the axial direction than the rotor (25) is 1.2H1 to 1.8H1. If the length (HG2+H3B) of the end portion (132) of the inertia body (130) protruding further in the axial direction than the rotor (25) is less than 1.2H1, the gap between the inertia body (130) and the insulator (24) is reduced, hindering the smooth flow of refrigerant, and the increase in the moment of inertia caused by the inertia body (130) is also reduced, causing the efficiency of the compressor to decrease. Conversely, if the length (HG2+H3B) of the end portion (132) of the inertia body (130) protruding further in the axial direction than the rotor (25) is greater than 1.28H1, the gap between the inertia body (130) and the compression portion (CU) is reduced, which hinders the smooth flow of the refrigerant, and the increase in the moment of inertia caused by the inertia body (130) becomes excessive, causing a problem in which the wear rate of the rotation shaft (30) increases during the rotation of the rotating body.

[0123] The inertia body (130) may be spaced apart in the axial direction from the lower part of the stator (21) and the upper part of the compression unit (CU), respectively. That is, the end portion (132) of the inertia body (130) with respect to the radial direction is positioned between the stator (21) and the compression unit (CU) with respect to the axial direction. As shown in FIG. 6, the bottom surface (131) of the inertia body (130) is spaced upward from the upper muffler (90). At the same time, the top surface (131') of the inertia body (130) is spaced downward from the inner insulation unit (24a) and the coil (23). As such, the inertia body (130) is positioned without interference with the stator (21) and the compression unit (CU), respectively, so it can rotate freely, and the refrigerant can flow smoothly between the inertia body (130) and the stator (21) and between the inertia body (130) and the compression unit (CU).

[0124] Referring to FIG. 7, the radial distance (BD2) from the center of the rotation axis (30) to the end portion (132) of the inertia body (130) may be greater than the radius (ID1) of the rotor (25). Here, the radius (ID1) of the rotor (25) refers to the radial distance from the center of the rotation axis (30) to the outer surface (25A) of the rotor (25). In FIG. 7, the reference numeral RG2 indicates the length to which the inertia body (130) protrudes further radially from the outer surface (25A) of the rotor (25). Thus, if the end portion (132) of the inertia body (130) protrudes further than the outer surface (25A) of the rotor (25), the inertia body (130) can provide a large moment of inertia to the rotating body. Drawing symbol RG3 indicates the radial separation distance between the end portion (132) of the inertial body (130) and the inner surface (11a) of the casing (10), and drawing symbol RG4 indicates the radial separation distance between the end portion (132) of the inertial body (130) and the outer insulating portion (24b).

[0125] The radial distance (BD2) from the center of the rotation axis (30) to the end portion (132) of the inertia body (130) may be larger than the radius of the rotor (25) (ID1) and smaller than the radius (ID2) of the stator (21). As shown in FIG. 7, the radial distance (BD2) from the center of the rotation axis (30) to the end portion (132) of the inertia body (130) is smaller than the radius (ID2) of the outer insulating portion (24b) of the insulator (24) constituting the stator (21). Accordingly, with respect to the radial direction (left-right direction in FIG. 7), the end portion (132) of the inertia body (130) may be positioned between the outer surface (25A) of the rotor (25) and the outer surface (21A) of the stator (21).

[0126] Meanwhile, the length of the inertia body (130) protruding radially from the weight body (110) needs to be appropriately set. In this embodiment, the length (RG2) of the inertia body (130) protruding further from the outer surface (25A) of the rotor (25) with respect to the radial direction can be determined in relation to the difference between the inner diameter of the casing (10) and the outer diameter of the rotor (25). In FIG. 7, the reference numeral RG1 represents half the difference between the inner diameter of the casing (10) and the outer diameter of the rotor (25). Alternatively, the reference numeral RG1 represents the difference between the radius of the casing (10) and the radius of the rotor (25).

[0127] At this time, the results of testing the cooling input and the wear rate of the rotating shaft (30) according to the length (RG2) in which the inertia body (130) protrudes radially from the outer surface (25A) of the rotor (25) in comparison to the difference (RG1) between the radius of the casing (10) and the radius of the rotor (25) are as shown in Table 1 below. Table 1 below shows the results of comparing this embodiment with a comparative example, in which a compressor with a general balance weight (100, 170) without the inertia body (130) was used as the comparative example.

[0128] In Table 1 below, "intermediate cooling" refers to the operating state (low-speed operation) of the compressor of the present embodiment installed in the air conditioner after it has started and the indoor temperature has reached the target value. Table 1 below summarizes the results of comparing the input values ​​of the present embodiment during intermediate cooling with the input values ​​of a conventional compressor (comparative example) during intermediate cooling.

[0129] And in Table 1 below, the wear rate of the rotating shaft (30) is measured when the compressor is operated continuously for a certain period of time (700 hours) or more, and the wear rate of the rotating shaft (30) applied to the compressor of this embodiment is compared with the wear rate of the rotating shaft (30) of a conventional compressor (comparative example).

[0130] Length difference (RG2) between the end portion of the inertia body (130) and the outer surface (25A) of the rotor (25) Input (%) of intermediate cooling compared to comparison example Wear rate (%) of the rotating shaft (30) compared to comparison example 0.05 RG1100.30.14 0.1 RG1100.60.06 0.2 RG198.70.03 0.3 RG198.10.02 0.4 RG198.30.04 0.5 RG197.90.03 0.6 RG198.00.06 0.7 RG198.20.05 0.8 RG1100.80.110.9 A101.20.13 1.0 RG1101.70.15 1.1 RG1102.60.14

[0131] As shown in Table 1 above, when the length (RG2) of the inertia body (130) protruding radially further than the outer surface (25A) of the rotor (25) is less than 0.2 times the difference (RG1) between the radius of the casing (10) and the radius of the rotor (25), there is no significant difference in the cooling input compared to the input of the comparative example. This means that the inertia body (130) cannot significantly increase the moment of inertia, and thus the efficiency of the compressor is not increased during low-speed operation of the compressor. On the other hand, when the length (RG2) of the inertia body (130) protruding radially further than the outer surface (25A) of the rotor (25) is 0.2 times or more and 0.7 times or less the difference (RG1) between the radius of the casing (10) and the radius of the rotor (25), the cooling input shows a significant difference compared to the input of the comparative example. That is, it means that the efficiency of the compressor is significantly improved during low-speed operation of the compressor. And, when the length (RG2) of the inertia body (130) protruding radially further than the outer surface (25A) of the rotor (25) is less than 0.2 times the difference (RG1) between the radius of the casing (10) and the radius of the rotor (25), there is no significant difference in the wear rate of the rotating shaft (30) compared to the wear rate of the rotating shaft (30) of the comparative example. This means that since the inertia body (130) does not significantly increase the moment of inertia, the difference in the wear rate of the rotating shaft (30) during the operation of the compressor is small. On the other hand, when the length (RG2) of the inertia body (130) protruding radially further than the outer surface (25A) of the rotor (25) becomes greater than 0.7 times the difference (RG1) between the radius of the casing (10) and the radius of the rotor (25), it can be seen that the wear rate of the rotating shaft (30) increases significantly. This means that as the size of the inertia body (130) becomes excessively large, the load (moment) applied to the rotation axis (30) also increases, and consequently, the rotation axis (30) wears out.

[0132] Consequently, when RG1 is defined as half the difference between the outer diameter of the casing (10) and the outer diameter of the rotor (25), and RG2 is defined as the difference in radial length between the end portion (132) of the inertia body (130) and the outer surface (25A) of the rotor (25), it is preferable that (RG1*0.7)>RG2>(RG1*0.2).

[0133] Meanwhile, the second balance weight (170) is positioned on the opposite side of the first balance weight (100) with respect to the axial direction. The second balance weight (170) can be coupled to the upper surface of the rotor (25). The second balance weight (170) can protrude in the opposite direction to the inertia body (130). Referring to FIG. 2, the second balance weight (170) protrudes in the first direction (left direction with respect to the drawing), whereas the inertia body (130) protrudes in the second direction (right direction with respect to the drawing).

[0134] FIGS. 11 and 12 show graphs of the results of comparing the present embodiment with a comparative example. First, FIG. 11 shows the results of comparing (i) cooling capacity (Fig. 11 (a)), (ii) input value (Fig. 11 (b)), and (iii) current value (Fig. 11 (c)) with a comparative example when the present embodiment is operated in cooling rated, intermediate cooling, heating rated, and intermediate heating states, respectively. Here, the cooling rated and heating rated states represent operating the compressor at maximum performance during cooling and heating operations, respectively, while the intermediate cooling and intermediate heating states represent operating the compressor at a low speed after reaching the target temperature. For the comparative example, a compressor with a conventional balance weight (100, 170) without the inertia body (130) was used.

[0135] As can be seen, the cooling capacity of the present embodiment is superior to that of the comparative example in all conditions. The first balance weight (100) to which the inertia body (130) is applied increases the efficiency of the compressor and improves operational performance. In addition, the input value and current value of the present embodiment are lower compared to the comparative example. In particular, the input value and current value of the present embodiment are significantly lower than those of the comparative example during the cooling intermediate state of low-speed operation. Therefore, the present embodiment can achieve high energy efficiency during low-speed operation.

[0136] FIG. 12 shows the results of comparing the magnitude of vibration according to the rotational speed per second of the rotor (25) in this embodiment (Fig. 12(a)) and the magnitude of noise according to the rotational speed per second of the rotor (25) (Fig. 12(b)) with a comparative example. Here, the magnitude of vibration is a value obtained by measuring the vibration of the discharge pipe (14) of the compressor using an accelerometer. The magnitude of noise is a measurement of noise in the low frequency band (1.00 kHz - 2.00 kHz) that is widely propagated to the outside of the compressor.

[0137] As shown in FIG. 12(a), it can be seen that the magnitude of vibration in this embodiment is smaller than in the comparative example. In particular, this embodiment shows a large difference from the vibration of the comparative example in the low range (30-40) of the rotational speed of the rotor (25) per second. This is the result of the moment of inertia increased by the inertia body (130) significantly reducing vibration during low-speed operation of the compressor.

[0138] Looking at FIG. 12(b), it can be seen that the noise level of this embodiment is lower than that of the comparative example. In particular, in this embodiment, the noise in the low frequency band generated during the operation of the compressor at most operating speeds is lower than that of the comparative example. This is the result of the moment of inertia increased by the inertia body (130) reducing noise along with vibration during the operation of the compressor.

[0139] FIG. 13 shows a cross-sectional view of the interior of a compressor to which a second embodiment of the lower balance weight (170) constituting the present invention is applied. To describe only the structure different from the preceding embodiment, the inertia body (130) may include a plurality of inertia bodies (130) having different radial lengths. In this embodiment, the inertia body (130) includes a first inertia body (130A) connected to the weight body (110) and having a larger diameter than the weight body (110).

[0140] A second inertial body (130B) is connected to the first inertial body (130A). The second inertial body (130B) is positioned at a location spaced further from the rotor (25) than the first inertial body (130A) with respect to the axial direction. The second inertial body (130B) has a larger diameter than the first inertial body (130A). Accordingly, the first inertial body (130A) and the second inertial body (130B) can form a kind of stepped structure.

[0141] In this embodiment, with respect to the axial direction, the first inertia body (130A) is positioned below the inner insulation part (24a), and the second inertia body (130B) is positioned below the outer insulation part (24b). At this time, the end portion (132) of the second inertia body (130B) may have a larger radius than the outer surface (21A) of the stator (21). That is, the end portion (132) of the second inertia body (130B) protrudes radially outward beyond the outer surface (21A) of the stator (21). In this way, the increase in the moment of inertia caused by the inertia body (130) can be made even greater.

[0142] FIG. 14 shows a cross-sectional view of the interior of a compressor to which a third embodiment of the lower balance weight (170) constituting the present invention is applied. To explain only the structure different from the previous embodiment, the insulator (24) may be omitted from the stator (21). As shown in FIG. 14, the coil (23) is wound on the stator core (22), and the insulator (24) surrounding the coil (23) is omitted.

[0143] In this embodiment, the inertia body (130) is positioned at the bottom of the coil (23). The inertia body (130) may be spaced axially from the bottom of the coil (23). The end portion (132) of the inertia body (130) may extend to a position that overlaps axially with the coil (23). The end portion (132) of the inertia body (130) may face directly the inner surface (11a) of the casing (10).

[0144] In this embodiment where the insulator is omitted, when 1 / 2 of the difference between the inner diameter of the casing (10) and the outer diameter of the rotor (25) is denoted as RG1 and 1 / 2 of the difference between the end portion (132) of the inertia body (130) and the outer diameter of the rotor (25) is denoted as RG2, it is preferable to have a relationship such that (RG1*0.95)>RG2>(RG1*0.2).

[0145] Length difference (RG2) between the end portion of the inertia body (130) and the outer surface (25A) of the rotor (25) Input (%) of intermediate cooling compared to comparison example Wear rate (%) of the rotating shaft (30) compared to comparison example 0.05 RG1100.30.17 0.1 RG1100.60.07 0.2 RG197.90.08 0.3 RG198.30.03 0.4 RG197.70.04 0.5 RG197.90.03 0.6 RG198.30.05 0.7 RG198.20.07 0.8 RG199.10.08 0.9A 98.90.05 0.95 RG199.50.09 1.0 RG1101.40.13

[0146] Table 2 above summarizes the test results of the compressor to which this embodiment is applied in the same manner as in Table 1 above. As shown in Table 2, when the length (RG2) of the inertia body (130) protruding radially further than the outer surface (25A) of the rotor (25) is less than 0.2 times the difference (RG1) between the radius of the casing (10) and the radius of the rotor (25), there is no significant difference in the cooling input compared to the input of the comparative example. This means that the inertia body (130) cannot significantly increase the moment of inertia, and thus cannot increase the efficiency of the compressor during low-speed operation. On the other hand, if the length (RG2) of the inertia body (130) protruding radially further than the outer surface (25A) of the rotor (25) is 0.2 times or more and 0.95 times or less of the difference (RG1) between the radius of the casing (10) and the radius of the rotor (25), the cooling intermediate input shows a significant difference compared to the input of the comparative example. That is, it means that the efficiency of the compressor is greatly improved during low-speed operation of the compressor. And, if the length (RG2) of the inertia body (130) protruding radially further than the outer surface (25A) of the rotor (25) is less than 0.2 times the difference (RG1) between the radius of the casing (10) and the radius of the rotor (25), there is no significant difference in the wear rate of the rotating shaft (30) compared to the wear rate of the rotating shaft (30) of the comparative example. This means that since the inertia body (130) does not significantly increase the moment of inertia, the difference in the wear rate of the rotating shaft (30) during the operation of the compressor is small. On the other hand, if the length (RG2) of the inertia body (130) protruding radially more than the outer surface (25A) of the rotor (25) becomes greater than 0.95 times the difference (RG1) between the radius of the casing (10) and the radius of the rotor (25), it can be seen that the wear rate of the rotating shaft (30) increases significantly. This means that as the size of the inertia body (130) becomes excessively large, the load (moment) applied to the rotating shaft (30) also increases, and consequently, the rotating shaft (30) wears out.

[0147] Consequently, when RG1 is defined as half the difference between the outer diameter of the casing (10) and the outer diameter of the rotor (25), and RG2 is defined as the difference in radial length between the end portion (132) of the inertia body (130) and the outer surface (25A) of the rotor (25), it is preferable that (RG1*0.95)>RG2>(RG1*0.2).

[0148] FIG. 15 shows a cross-sectional view of the interior of a compressor to which a fourth embodiment of the lower balance weight (170) constituting the present invention is applied. To describe only the structure different from the previous embodiment, the first balance weight (100) is arranged in a circular shape at the bottom of the rotor (25). The first balance weight (100) can continuously surround the bottom of the rotor (25) to form a closed curve.

[0149] In this embodiment, a part (140) of the weight body (110) may be provided on the opposite side of the inertia body (130) centered on the rotation axis (30). The part of the weight body (110) may become the cover (140) of the first balance weight (100). As shown in FIG. 15, the cover (140) of the first balance weight (100) may form an internal space (141) that is empty inside.

[0150] The cover (140) of the first balance weight (100), which is part of the weight body (110) positioned opposite the inertia body (130), has a smaller mass than the remaining part of the weight body (110) to which the inertia body (130) is connected. Accordingly, the side where the inertia body (130) is positioned can maintain a larger moment of inertia on the rotating body. Additionally, the cover (140) of the first balance weight (100) can serve to guide the flow of refrigerant discharged from the compression unit (CU).

[0151] FIGS. 16 and FIGS. 17 respectively illustrate a fifth embodiment of the lower balance weight (170) constituting the present invention. To describe only the structure different from the previous embodiment, in this embodiment, the weight body (110) is provided with a disc-shaped end plate portion (118) that is coupled to the rotor (25). The end plate portion (118) is connected in a circumferential direction from the weight body (110). The end plate portion (118) causes the weight body (110) to form a continuous circle overall.

[0152] The end plate portion (118) can be assembled to the rotor core (26) using a first fastener (B1) while stacked on the rotor core (26). The end plate portion (118) can prevent the permanent magnet (27) from being separated from the rotor core (26). Thus, in this embodiment, a separate end plate (28) is omitted, and the first balance weight (100) can perform the function of the end plate (28).

[0153] As shown in FIG. 17, the inertia body (130) is spaced apart from the end plate portion (118) in the axial direction. In terms of the radial direction, the end plate portion (118) can be seen to protrude in opposite directions to the inertia body (130). Additionally, in terms of the circumferential direction, the end plate portion (118) and the inertia body (130) have different circumferential ranges in the first balance weight (100). Reference numeral 118' indicates an assembly hole for fastening the first fastener (B1).

[0154] FIGS. 18 and FIGS. 19 respectively illustrate a sixth embodiment of the lower balance weight (170) constituting the present invention. To describe only the structure different from the previous embodiment, the inclined portion (120) may be omitted from the first balance weight (100). Compared to the previous embodiment, the inclined portion (120) is not provided along the edge of the weight body (110), and the lower surface of the weight body (110) and the side surface (112) of the weight body (110) may be connected in a direction orthogonal to each other. Reference numeral 120 indicates a groove portion to avoid interference between the first balance weight (100) and the rotor (25).

[0155] FIGS. 20 and FIGS. 21 respectively illustrate a seventh embodiment of the lower balance weight (170) constituting the present invention. To describe only the structure different from the preceding embodiment, the first balance weight (100) may be integrally provided with an end plate portion (118). The end plate portion (118) is connected in a circumferential direction from the weight body (110). The end plate portion (118) causes the weight body (110) to form a continuous circle overall.

[0156] Referring to FIG. 20, in this embodiment, the angle between the two ends (134) of the weight body (110) passing through the center of the rotation axis (30) is greater than 180 degrees. Here, the two ends (134) of the weight body (110) refer to the two end portions based on the circumferential direction of the rotor (25). If the angle between the two ends (134) of the weight body (110) is greater than 180 degrees, the volume occupied by the inertia body (130) can also increase.

[0157] An inclined portion (120) may be formed at the edge of the lower surface of the weight body (110), such that the distance from the rotation axis (30) gradually increases toward the compression portion (CU). The inclined portion (120) extends along the edge of the lower surface and has an inclined or curved shape. In this embodiment, the inclined portion (120) is formed so that its area gradually increases along the rotational direction of the first balance weight (100). Based on FIG. 20, the inclined portion (120) has a shape in which its area increases in a counterclockwise direction.

[0158] FIG. 22 illustrates, in a side view, the structure of the eighth embodiment of the lower balance weight (170) constituting the present invention. To describe only the structure different from the preceding embodiment, the first balance weight (100) is provided with an inertia body (130). The inertia body (130) protrudes radially from the weight body (110) of the first balance weight (100). At this time, the inertia body (130) is provided at a position spaced upward from the bottom of the weight body (110). Referring to FIG. 22, the bottom surface (131) of the inertia body (130) has a height spaced upward from the bottom of the weight body (110).

[0159] FIG. 23 is a side view illustrating the structure of a ninth embodiment of a lower balance weight (170) constituting the present invention. To describe only the structure different from the preceding embodiment, the first balance weight (100) is provided with an inertia body (130). The length of the inertia body (130) protruding radially along the axial direction varies. Looking at FIG. 23, the length of the inertia body (130) protruding radially increases as it goes from the bottom to the top. As another example, the length of the inertia body (130) protruding radially may increase as it goes from the top to the bottom.

[0160] Although the preceding embodiment described a rotary compressor as an example, the present invention can be applied to various types of compressors having an eccentric part, such as screw compressors.

[0161] The foregoing description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by such embodiments. The scope of protection of the present invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention.

Claims

1. Casing; A drive unit disposed inside the above casing and comprising a stator and a rotor that rotates a rotation axis; A compression section disposed inside the casing so as to be spaced apart in the axial direction of the rotation axis and forming a compression space in which a refrigerant is compressed; and It includes a balance weight that rotates together with the rotor mentioned above, The above balance weight is A weight body coupled to the rotor or the rotation axis, and A compressor comprising an inertia body provided at the lower part of the balance weight facing the compression section and protruding further radially outward from the weight body.

2. A compressor according to claim 1, wherein the radial distance from the center of the rotation axis to the end portion of the inertia body is greater than the radius of the rotor.

3. A compressor according to claim 1, wherein the radial distance from the center of the rotation axis to the end portion of the inertia body is greater than the radius of the rotor and smaller than the radius of the stator.

4. The compressor of claim 1, wherein the inertia body is positioned below the stator with respect to the axial direction.

5. The inertia body of claim 1, a compressor spaced apart in the axial direction from the lower part of the stator and the upper part of the compression part, respectively.

6. The compressor according to claim 1, wherein the end portion of the inertial body with respect to the radial direction is disposed between the stator and the compression portion with respect to the axial direction.

7. In claim 1, the weight body extends in an arc shape along the circumferential direction of the rotor, and The above inertial body is a compressor that extends in an arc shape along the circumferential direction of the above weight body.

8. A compressor according to claim 1, wherein the axial thickness of the inertia body is thinner than the axial thickness of the weight body.

9. In claim 1, the weight body is provided with a disc-shaped end plate portion coupled to the rotor, and The above inertial body is a compressor spaced apart from the above end plate portion in the axial direction.

10. In claim 1, the weight body is provided with a coupling surface coupled to the rotor, and A compressor having an inclined portion formed on the edge of the lower surface of the weight body formed on the opposite side of the above-mentioned coupling surface, such that the distance from the rotation axis gradually increases toward the compression portion.

11. In claim 10, the inertial body and the inclined portion are each provided along the edge of the lower surface, and The above inertial body protrudes from the outer edge of the lower surface toward the inner surface of the casing, and A compressor formed on the inner edge of the lower surface facing the outer surface of the rotation shaft or the outer surface of the bearing of the compression part.

12. In claim 10, the weight body has a fastening hole formed therein for coupling the balance weight to the rotor, and In the above weight body, a fastening guide wall surrounding the fastening hole is formed in the axial direction, and The above inclined portion is a compressor connected to the above-mentioned fastening guide wall.

13. In claim 1, the inertial body A first inertia body connected to the weight body and protruding further radially outward than the weight body; and It includes a second inertial body connected to the first inertial body and positioned at a location spaced apart from the rotor with respect to the axial direction compared to the first inertial body. A compressor in which the radial length from the rotation axis to the end portion of the second inertial body is longer than the radial length from the rotation axis to the end portion of the first inertial body.

14. In claim 1, the weight body is arranged in a circular shape at the lower part of the rotor, and A compressor in which a portion of the weight body positioned opposite the inertia body around the aforementioned axis of rotation has a lighter weight than the remaining portion of the weight body to which the inertia body is connected.

15. In claim 1, the stator A coil wound around a core; and Insulator forming the winding space of the above coil; including The above insulator includes an inner insulating portion forming the inner boundary of the winding space and an outer insulating portion forming the outer boundary of the winding space, and The end portion of the above-mentioned inertial body is a compressor positioned between the inner insulating portion and the outer insulating portion with respect to the axial direction.

16. A compressor according to claim 1, wherein the end portion of the inertial body is disposed between the inner insulating portion and the outer insulating portion with respect to the radial direction.

17. In claim 1, the stator A coil wound around a core; and Insulator forming the winding space of the above coil; including The end portion of the above-mentioned inertial body is positioned below the insulator with respect to the above-mentioned axial direction, and A compressor in which the end portion of the above-mentioned inertial body is positioned outside the insulator with respect to the above-mentioned radial direction.

18. In claim 1, the stator A coil wound around a core; and Insulator forming the winding space of the above coil; including The above insulator includes an inner insulating portion forming the inner boundary of the winding space and an outer insulating portion forming the outer boundary of the winding space, and The end portion of the above-mentioned inertial body is positioned between the inner insulating portion and the outer insulating portion with respect to the above-mentioned radial direction, and Half of the difference between the inner diameter of the casing and the outer diameter of the rotor is denoted as RG1, and When the difference in radial length between the end portion of the inertial body and the outer surface of the rotor is denoted as RG2, A compressor having the relationship (RG1*0.7)>RG2>(RG1*0.2).

19. In claim 1, the rotating shaft is provided with an eccentric portion disposed in the compression space of the compression portion, and A compressor in which the inertial body protrudes in the opposite direction of the eccentric part based on the above radial direction.

20. Casing; A drive unit disposed inside the above casing and comprising a stator and a rotor that rotates a rotation axis; A compression section disposed inside the casing so as to be spaced apart in the axial direction of the rotation axis and forming a compression space in which a refrigerant is compressed; and It includes a balance weight that rotates together with the rotor mentioned above, The balance weight is provided with an inertia protrusion that protrudes further outwardly in a radial direction from the balance weight along the circumferential direction of the balance weight. A compressor in which the first surface of the inertia protrusion faces the compression section, and the second surface of the inertia protrusion formed on the opposite side of the first surface is arranged to overlap with the stator in the axial direction.

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