SPIRAL COMPRESSOR

Description

Technical field

[0001] The present invention relates to a scroll compressor, and more particularly, to a scroll compressor that supplies oil to a compression chamber using a difference between internal pressure of a casing and internal pressure of the compression chamber.Background Art

[0002] A compressor applied to a refrigeration cycle of a refrigerator or an air conditioner serves to compress refrigerant gas and transmit the compressed refrigerant gas to a condenser. A rotary compressor or a scroll compressor is mainly applied to an air conditioner. Recently, the scroll compressor has been applied not only to the air conditioner but also to a compressor for hot water supply which requires a higher compression ratio than the air conditioner.

[0003] Scroll compressors may be classified into a hermetic scroll compressor in which a drive unit (or motor unit) and a compression unit are all disposed inside a casing, and an open scroll compressor in which a drive unit (or motor unit) is disposed outside a casing and the compression unit is merely disposed inside the casing.

[0004] Scroll compressors may be classified into a top-compression type or a bottom-compression type depending on positions of a drive motor constituting a drive unit or a motor unit and a compression unit. The top-compression type is configured such that the compression unit is located above the drive motor, whereas the bottom-compression type is configured such that the compression unit is located below the drive motor. This classification is made based on an example in which a casing is vertically installed. For convenience, when the casing is horizontally installed, a left side may be defined as a top and a right side as a bottom.

[0005] Scroll compressors may be divided into a low-pressure type scroll compressor in which an inner space of a casing having a compression unit forms suction pressure and a high-pressure type scroll compressor in which the inner space of the casing forms discharge pressure. The top-compression type scroll compressor may be configured as a low-pressure type or a high-pressure type, but the bottom-compression type scroll compressor is generally configured as a high-pressure type scroll compressor in consideration of a position of a refrigerant suction pipe.

[0006] The high-pressure type scroll compressor supplies oil in the casing to the compression chamber by using a difference (hereinafter, referred to as a differential pressure) between internal pressure of the casing and internal pressure of the compression chamber as the inner space of the casing forms discharge pressure. Accordingly, an oil supply pump can be simplified in the high-pressure type scroll compressor. Therefore, a scroll compressor will be understood as a bottom-compression and high-pressure type scroll compressor, unless otherwise specified.

[0007] Patent Document 1 (Korean Patent Publication No. 10-2018-0138479) discloses a scroll compressor using differential pressure. Patent Document 1 shows an example in which oil suctioned upward through an oil passage of a rotation shaft is supplied to a compression chamber via an intermediate pressure chamber.

[0008] In the scroll compressor, volume loss due to an excessive oil supply may occur when oil is supplied to the compression chamber before suction is completed. For this reason, in an oil supply structure using differential pressure, the location of an oil supply passage is set so that oil is supplied to the compression chamber after the suction is completed.

[0009] However, in the case of the related art scroll compressor, under abnormal operating conditions, such as rapid starting, the temperature of a compression unit may rise up to 40 degrees higher than the temperature of a high-pressure side of a refrigeration cycle due to friction between wraps. Then, the temperature of a suction-side wrap also rapidly increases, causing the suction-side wrap to be drastically deformed, which may significantly increase friction loss and / or wear between an end surface of the suction-side wrap and an end plate portion facing the end surface. When an orbiting scroll is manufactured using a material having a higher coefficient of friction than a fixed scroll, the friction loss and / or wear may increase further, which may cause a decrease in compression efficiency and / or reliability issues.

[0010] In the related art scroll compressor, oil is supplied into a compression chamber via an intermediate pressure chamber, which forms back pressure with respect to the orbiting scroll. This may make it impossible to supply oil during an operation at a low-pressure ratio in which an operation pressure ratio is 1.3 or less. As a result, the operation at the low-pressure ratio, in which the operation pressure ratio is 1.3 or less, is limited, and efficiencies of the scroll compressor and an air conditioner employing the same may be lowered.

[0011] JP 2016 145522 A discloses a scroll compressor designed to improve sealing performance in the compression chamber while reducing suction heating loss.Disclosure of Invention Technical Problem

[0012] An aspect of the present invention is to provide a scroll compressor capable of reducing friction loss and / or wear between an end surface of a wrap and an end plate portion facing the end surface even in abnormal operation conditions, such as rapid starting.

[0013] Another aspect of the present invention is to provide a scroll compressor capable of smoothly supplying oil to an area between an end surface of a wrap and an end plate portion facing the end surface.

[0014] Another aspect of the present invention is to provide a scroll compressor capable of smoothly supplying oil to a gap between a suction-side wrap with a relatively great thermal deformation and an end plate portion facing the suction-side wrap.

[0015] Another aspect of the present invention is to provide a scroll compressor capable of suppressing wear of an orbiting wrap when an orbiting scroll is made of a material having a higher coefficient of thermal expansion than a fixed scroll.

[0016] Another aspect of the present invention is to provide a scroll compressor capable of smoothly supplying oil stored in an inner space of a casing to a compression chamber by using a pressure difference between an inner space of the casing and the compression chamber while performing an operation at a low-pressure ratio, in which an operation pressure ratio is 1.3 or less.Solution to Problem

[0017] The present invention is defined by the appended claims. In the following description, there is further provided a scroll compressor that includes a casing, a rotation shaft, an orbiting scroll, a fixed scroll, and a main frame. A certain amount of oil is stored in the casing. The rotation shaft is arranged in an inner space of the casing, and an oil passage is formed in the rotation shaft. The orbiting scroll includes an orbiting end plate portion coupled to the rotation shaft to perform an orbiting motion, and an orbiting wrap arranged on one side surface of the orbiting end plate portion. The fixed scroll includes a fixed wrap arranged on one side surface of a fixed end plate portion and engaged with the orbiting wrap to form a compression chamber. The main frame is arranged on an opposite side of the fixed scroll with the orbiting scroll arranged therebetween, fixed to the inner space of the casing, and forming an intermediate pressure chamber together with the orbiting scroll and the fixed scroll to press the orbiting scroll toward the fixed scroll. The scroll compressor further includes an oil supply passage to communicate between the intermediate pressure chamber and the compression chamber, such that oil in the intermediate pressure chamber is partially guided into the compression chamber. An oil supply groove is formed in an end surface of the orbiting wrap facing the fixed end plate portion to communicate with the oil supply passage. The oil supply groove is recessed by a preset depth along a height direction of the wrap and extend along a formation direction of the wrap. With the configuration, under abnormal operating conditions, such as rapid starting, oil may be supplied into a gap between an end surface of the wrap and an end plate portion opposing the end surface through an oil supply groove formed in the end surface of the wrap. Accordingly, friction loss and / or wear between the end surface of the wrap and the end plate portion may be reduced even under the abnormal operating conditions.

[0018] For example, the oil supply groove may be formed in a range of a rotation angle of 300° of the rotation shaft inwardly along a formation direction of the orbiting wrap from a point which is spaced by a preset sealing length apart from an outer end of the orbiting wrap. With the configuration, oil may be smoothly supplied into a gap between a suction-side wrap, on which a relatively great thermal deformation occurs, and an end plate portion facing the suction-side wrap, thereby reducing friction loss and / or wear on the suction-side wrap.

[0019] As another example, one end of the oil supply passage communicating with the compression chamber may be formed such that at least a portion of the one end is located in an orbiting radius range of the oil supply groove per each pivoting of the orbiting scroll. With the configuration, oil which flows into the compression chamber through the oil supply passage may be continuously supplied into the oil supply groove, thereby reducing friction loss and / or wear on the suction-side wrap.

[0020] For example, an inner diameter of the oil supply passage communicating with the compression chamber may be smaller than a wrap thickness of the orbiting wrap, and a width of the oil supply groove may be smaller than or equal to the inner diameter of the oil supply passage. With the configuration, areas of end surfaces formed on opposite sides of the oil supply groove may be secured, thereby maintaining a sealing distance between the oil supply groove and the compression chamber and / or between compression chambers.

[0021] In another example, the oil supply groove may have a same cross-sectional area along a formation direction of the orbiting wrap. This may facilitate the oil supply groove to be formed in the end surface of the orbiting wrap while maintaining a uniform area of the end surface of the wrap.

[0022] In still another example, the oil supply groove may have different cross-sectional areas along the formation direction of the orbiting wrap. This may allow more oil to be supplied to a portion where a great thermal deformation occurs, thereby more effectively reducing friction loss and / or wear.

[0023] For example, the oil supply groove may include: a first oil supply groove communicating with the oil supply passage; and a second oil supply groove communicating with the first oil supply groove and formed at an outer side in the formation direction of the orbiting wrap, compared to the first oil supply groove. A cross-sectional area of the second oil supply groove may be larger than a cross-sectional area of the first oil supply groove. This may allow more oil to be supplied to a portion, such as a suction-side wrap, on which a relatively great thermal deformation occurs, thereby reducing friction loss and / or wear on the suction-side wrap.

[0024] The oil supply groove may include: a first oil supply groove communicating with the oil supply passage; and a second oil supply groove communicating with the first oil supply groove and formed at an outer side in the formation direction of the orbiting wrap, compared to the first oil supply groove. A cross-sectional area of the second oil supply groove may be smaller than a cross-sectional area of the first oil supply groove. With the configuration, an area of the end surface may increase at a portion, such as a suction-side wrap, on which a relatively great thermal deformation occurs, thereby securing reliability at the suction-side wrap.

[0025] In another example, the orbiting scroll may be made of a material having a greater coefficient of thermal expansion than that of the fixed scroll. This may reduce the weight of the orbiting wrap so as to improve compression efficiency and suppress wear of the end surface of the orbiting scroll so as to enhancing reliability of the orbiting scroll.

[0026] As another example, the oil supply passage may be isolated from the intermediate pressure chamber and allow the oil passage to communicate with the compression chamber. Accordingly, an inner space of a casing may communicate directly with the compression chamber without passing through the intermediate pressure chamber, and thus oil stored in the inner space the casing may be smoothly supplied to the compression chamber even in a state where an operating pressure ratio is 1.3 or less, namely, even if a differential pressure between the inner space and the compression chamber is not great.

[0027] In an example, the oil supply passage includes a first oil supply passage and a second oil supply passage. The first oil supply passage is arranged in the orbiting scroll, and one end thereof communicates with the oil passage of the rotation shaft. The second oil supply passage is arranged in the fixed scroll and has one end communicating with the first oil supply passage and another end communicating with the compression chamber. With this configuration, the oil supply passage may be isolated from the intermediate pressure chamber, and thus the inner space of the casing may directly communicate with the compression chamber without passing through the intermediate pressure chamber.

[0028] At least a portion of another end of the first oil supply passage and at least a portion of the one end of the second oil supply passage may continuously communicate with each other during the orbiting motion of the orbiting scroll. With this configuration, even though the oil supply passage does not communicate with the intermediate pressure chamber, oil in the casing can be guided to be continuously supplied to the compression chamber.

[0029] Another end of the first oil supply passage may pass through a first thrust surface of the orbiting scroll facing the fixed scroll, and the one end of the second oil supply passage may pass through a second thrust surface of the fixed scroll facing the orbiting scroll. With this configuration, the oil supply passages can always communicate with each other without communicating with the intermediate pressure chamber.

[0030] At least one of the another end of the first supply oil supply passage and the one end of the second oil supply passage facing the another end of the first oil supply passage may be formed in a non-circular cross-sectional shape. With this configuration, even if a thrust surface is narrowed due to the shape of a hybrid wrap or an elliptical wrap, the oil supply passages can always communicate with each other without communicating with the intermediate pressure chamber.

[0031] The another end of the first oil supply passage may extend long along the first thrust surface in a circumferential direction. The one end of the second oil supply passage may extend long along the second thrust surface in the circumferential direction. With the configuration, the first oil supply passage and the second oil supply passage can continuously communicate with each other even during the orbiting motion of the orbiting scroll, so that oil stored in the inner space of the casing can be smoothly supplied to the compression chamber even in an operation at a low-pressure ratio.

[0032] A cross-sectional area of the one end of the second oil supply passage may be larger than a cross-sectional area of the another end of the first oil supply passage. As an oil supply passage having a larger cross-sectional area is formed in a thrust surface, which has a relatively wider margin area, the first oil supply passage and the second oil supply passage can continuously communicate with each other even during the orbiting motion of the orbiting scroll.

[0033] The first oil supply passage may include a first orbiting oil supply part, a second orbiting oil supply part, and a third orbiting oil supply part. The first orbiting oil supply part may have one end communicating with the oil passage and another end extending toward an outer circumferential surface of the orbiting scroll. The second orbiting oil supply part may have one end communicating with the first orbiting oil supply part and another end open toward the fixed scroll. The third orbiting oil supply part may extend in a circumferential direction from the another end of the second orbiting oil supply part facing the fixed scroll to communicate with the second oil supply passage. With the configuration, the first oil supply passage can be easily formed in the orbiting scroll even without communicating with the intermediate pressure chamber.

[0034] A radial width of the third orbiting oil supply part may be larger than or equal to an inner diameter of the second orbiting oil supply part. This can increase a cross-sectional area of the third orbiting oil supply part formed on the thrust surface as wide as possible, which can be advantageous in that the first oil supply passage continuously communicates with the second oil supply passage.

[0035] An inner diameter of the second orbiting oil supply part may be smaller than or equal to an inner diameter of the first orbiting oil supply part. This can facilitate machining of the first orbiting oil supply part and reduce pressure of oil passing through the second orbiting oil supply part, thereby enhancing an oil supply effect in an operation at a low-pressure ratio.

[0036] The second oil supply passage may include a first fixed oil supply part, a second fixed oil supply part, a third fixed oil supply part, and a fourth fixed oil supply part. The first fixed oil supply part may have one end open on a surface of the fixed scroll facing the orbiting scroll to communicate with the first oil supply passage, and another end extending toward another surface of the fixed scroll. The second fixed oil supply part may have one end communicating with the another end of the first fixed oil supply part and another end extending toward the compression chamber. The third fixed oil supply part may have one end communicating with the second fixed oil supply part and another end open to communicate with the compression chamber. The fourth fixed oil supply part may extend in the circumferential direction from the one end of the first fixed oil supply part facing the orbiting scroll to communicate with the first oil supply passage. With the configuration, the second oil supply passage can be easily formed in the fixed scroll even without communicating with the intermediate pressure chamber.

[0037] A radial width of the fourth fixed oil supply part may be larger than an inner diameter of the first fixed oil supply part. This can increase a cross-sectional area of the fourth fixed oil supply part formed on the thrust surface as wide as possible, which can be advantageous in that the second oil supply passage continuously communicates with the first oil supply passage.

[0038] The fourth fixed oil supply part may be formed such that a cross-sectional area on a side adjacent to the first fixed oil supply part is larger than a cross-sectional area of another side far away from the first fixed oil supply part. As the fourth fixed oil supply part is formed wide on a relatively wide side even on the thrust surface of the fixed scroll, the size of the fourth fixed oil supply part can be as large as possible. This can be more advantageous in view of allowing the second oil supply passage to continuously communicate with the first oil supply passage.Advantageous Effects of Invention

[0039] In a scroll compressor according to the invention, there is provided an oil supply passage which communicates between an intermediate pressure chamber and a compression chamber so as to guide some of oil in the intermediate pressure chamber to the compression chamber, an orbiting wrap has an oil supply groove formed in an end surface thereof to be in communication with the oil supply passage, and the oil supply groove is recessed by a preset depth in a height direction of the wrap and extends in a formation direction of the wrap. With the configuration, under abnormal operating conditions, such as rapid starting, oil may be supplied into a space between the end surface of the wrap and an end plate portion opposing the end surface through the oil supply groove formed in the end surface of the wrap. Accordingly, friction loss and / or wear between the end surface of the wrap and the end plate portion may be reduced even under the abnormal operating conditions.

[0040] An oil supply groove may be formed in a range of a rotation angle of 300° of a rotation shaft inwardly along a formation direction of an orbiting wrap from a point which is spaced by a preset sealing length apart from an outer end of the orbiting wrap. With the configuration, oil may be smoothly supplied into a space between a suction-side wrap, on which a relatively great thermal deformation occurs, and the end plate portion facing the wrap, thereby reducing friction loss and / or wear on the suction-side wrap.

[0041] One end of the oil supply passage communicating with the compression chamber may be formed such that at least a portion of the one end is located in an orbiting radius range of the oil supply groove per each pivoting of the orbiting scroll. With the configuration, oil which flows into the compression chamber through the oil supply passage may be continuously supplied into the oil supply groove, thereby reducing friction loss and / or wear on the suction-side wrap.

[0042] An oil supply groove may have a same cross-sectional area along the formation direction of the orbiting wrap. This may facilitate the oil supply groove to be formed in the end surface of the orbiting wrap while maintaining a uniform area of the end surface of the wrap.

[0043] An oil supply groove may have different cross-sectional areas along the formation direction of the orbiting wrap. This may allow more oil to be supplied to a portion where a great thermal deformation occurs, thereby more effectively reducing friction loss and / or wear.

[0044] The oil supply passage may be isolated from the intermediate pressure chamber and communicate between the oil passage and the compression chamber. As an inner space of a casing communicates directly with the compression chamber without passing through the intermediate pressure chamber, even in a state where an operating pressure ratio is 1.3 or less, namely, even if a differential pressure between the inner space and the compression chamber is not great, oil stored in the inner space can be smoothly supplied to the compression chamber.Brief Description of Drawings

[0045] FIG. 1 is a longitudinal sectional view of a bottom-compression type scroll compressor according to an embodiment of the invention. FIG. 2 is an exploded perspective view of an orbiting scroll and a fixed scroll in FIG. 1. FIG. 3 is a planar view of the orbiting scroll in FIG. 2. FIG. 4 is a cross-sectional view taken along line "IX-IX" of FIG. 3. FIG. 5 is a planar view of the fixed scroll in FIG. 2. FIG. 6 is a cross-sectional view taken along the line "X-X" of FIG. 5. FIG. 7 is a planar view of a state, in which the orbiting scroll and the fixed scroll are coupled, viewed from the side of the fixed scroll. FIG. 8 is an enlarged schematic view of the relationship between a third orbiting oil supply part and a fourth fixed oil supply part according to the change in rotation angle in FIG. 7. FIG. 9 is a planar view of a state, in which the orbiting scroll and the fixed scroll are coupled, viewed from the side of the orbiting scroll. FIG. 10 is a schematic view of the communication relationship between an oil supply passage and an oil supply groove in FIG. 9. FIG. 11 is a planar view of an orbiting scroll to explain another embodiment of an oil supply groove. FIG. 12 is a planar view of an orbiting scroll to explain another embodiment of an oil supply groove. Mode for the Invention

[0046] Description will now be given in detail of a scroll compressor disclosed herein, with reference to the accompanying drawings. In the following description, a description of some components may be omitted to clarify features of the present invention.

[0047] In addition, the term "upper side" used in the following description refers to a direction away from a support surface for supporting a scroll compressor according to an implementation of the present invention, that is, a direction toward a drive part (motor part or drive motor) when viewed based on the drive part unit (motor part or drive motor) and a compression part. The term "lower side" refers to a direction toward the support surface, that is, a direction toward the compression unit when viewed based on the drive unit (motor unit or drive motor) and the compression unit.

[0048] The term "axial direction" used in the following description refers to a lengthwise (longitudinal) direction of a rotation shaft. The "axial direction" may be understood as an up and down (or vertical) direction. The term "radial direction" refers to a direction that intersects the rotation shaft.

[0049] In addition, in the following description, a hermetic scroll compressor in which a drive part (motor part or drive motor) and a compression part are disposed in a casing will be described as an example. However, the present disclosure may be applied equally to an open type compressor in which a drive unit (motor unit or drive motor) is disposed outside a casing and connected to a compression unit disposed inside the casing.

[0050] In addition, a description will be given of a bottom-compression type scroll compressor in which a drive unit (a motor unit or a drive motor) and a compression unit are arranged vertically in an axial direction and a compression unit is located below the motor unit. However, the present disclosure may be applied equally to a horizontal scroll compressor in which a drive unit (motor unit or drive motor) and a compression unit are disposed in left and right directions, as well as a top-compression type scroll compressor in which the compression unit is located above the drive unit (motor unit or drive motor).

[0051] In addition, a description will be given of a high-pressure and bottom-compression type scroll compressor in which a refrigerant suction pipe defining a suction passage is directly connected to a compression unit and a refrigerant discharge pipe communicates with an inner space of a casing to form discharge pressure in the inner space of the casing.

[0052] FIG. 1 is a longitudinal sectional view of an inner structure of a bottom-compression type scroll compressor in accordance with an embodiment.

[0053] Referring to FIG. 1, a high-pressure and bottom-compression type scroll compressor (hereinafter, abbreviated as a scroll compressor) according to an embodiment of the present invention includes a drive motor 120 constituting a motor unit disposed in an upper-half portion of a casing 110, and a main frame 130, an orbiting scroll 140, a fixed scroll 150, and a discharge cover 160 sequentially disposed below the drive motor 120. In general, the drive motor 120 may constitute the motor unit, as described above, and the main frame 130, the orbiting scroll 140, the fixed scroll 150, and the discharge cover 160 may constitute a compression unit C.

[0054] The drive motor 120 constituting the motor unit is coupled to an upper end of a rotation shaft 125 to be described later, and the compression unit C is coupled to a lower end of the rotation shaft 125. Accordingly, the compressor 10 may have the bottom-compression type structure described above, and the compression unit C is connected to the drive motor 120 by the rotation shaft 125 to be operated by rotational force of the drive motor 120. Therefore, since the drive motor 120 can be understood as a drive unit for driving the compression unit C, the drive motor may also be described as a motor unit or a drive unit in the following description.

[0055] Referring to FIG. 1, the casing 110 may include a cylindrical shell 111, an upper shell 112, and a lower shell 113. The cylindrical shell 112 is formed in a cylindrical shape with upper and lower ends open. The upper shell 112 is coupled to cover the open upper end of the cylindrical shell 111. The lower shell 113 is coupled to cover the open lower end of the cylindrical shell 111. Accordingly, the inner space 110a of the casing 110 is sealed. The sealed inner space 110a of the casing 110 is divided into a lower space S1 and an upper space S2 based on the drive motor 120.

[0056] The lower space S1 may be a space defined below the drive motor 120. The lower space S1 may be divided into an oil storage space S11 and an outflow space S12 with the compression unit C therebetween.

[0057] The upper space S2 may be a space defined above the drive motor 120 to form an oil-separating space in which oil is separated from refrigerant discharged from the compression unit C. A refrigerant discharge pipe 116 to be explained later communicates with the upper space S2.

[0058] The drive motor 120 and the main frame 130 are fixedly inserted into the cylindrical shell 111. An outer circumferential surface of the drive motor 120 and an outer circumferential surface of the main frame 130 may be respectively provided with oil return passages (no reference numerals given) each spaced apart from an inner circumferential surface of the cylindrical shell 111 by a preset distance.

[0059] A refrigerant suction pipe 115 is coupled through a side surface of the cylindrical shell 111. Accordingly, the refrigerant suction pipe 115 is coupled through the cylindrical shell 111 forming the casing 110 in a radial direction.

[0060] An inner end of the refrigerant discharge pipe 116 is coupled through an upper portion of the upper shell 112 to communicate with the inner space 110a of the casing 110, specifically, the upper space S2 defined above the drive motor 120.

[0061] One end portion of an oil circulation pipe (not illustrated) may be coupled through a lower-half portion of the lower shell 113 in a radial direction. Both ends of the oil circulation pipe may be open, and another end portion of the oil circulation pipe may be coupled through the refrigerant suction pipe 115. An oil circulation valve (not illustrated) may be installed in a middle portion of the oil circulation pipe.

[0062] Referring to FIG. 1, the drive motor 120 includes a stator 121 and a rotor 122. The stator 121 is fitted onto the inner circumferential surface of the cylindrical shell 111, and the rotor 122 is rotatably disposed in the stator 121.

[0063] The stator 121 includes a stator core 1211 and a stator coil 1212.

[0064] The stator core 1211 is formed in an annular shape or a hollow cylindrical shape and is shrink-fitted onto the inner circumferential surface of the cylindrical shell 111.

[0065] The stator coil 1212 may be wound around the stator core 1211 and may be electrically connected to an external power source through a power cable (no reference numeral given) that is coupled through the casing 110. An insulator 1213, which is an insulating member, is inserted between the stator core 1211 and the stator coil 1212.

[0066] The rotor 122 includes a rotor core 1221 and permanent magnets 1222.

[0067] The rotor core 1221 is rotatably inserted into the stator core 1211 with a preset gap (no reference numeral given) therebetween. The permanent magnets 1222 are embedded in the rotor core 1222 at preset distances along the circumferential direction.

[0068] A balance weight 123 may be coupled to a lower end of the rotor core 1221. Alternatively, the balance weight 123 may be coupled to the rotation shaft 125. This embodiment illustrates an example in which the balance weight 123 is coupled to the rotation shaft 125. The balance weight 123 is disposed on each of a lower end side and an upper end side of the rotor, and the two balance weights 123 may be installed symmetrically to each other.

[0069] The rotation shaft 125 is coupled to the center of the rotor core 1221. An upper end portion of the rotation shaft 125 is press-fitted to the rotor 122, and a lower end portion of the rotation shaft 125 is rotatably inserted into the main frame 130 to be supported in the radial direction.

[0070] The main frame 130 is provided with a main bearing (no reference numeral given) configured as a bush bearing to support the lower end portion of the rotation shaft 125. Accordingly, a portion, which is inserted into the main frame 130, of the lower end portion of the rotation shaft 125 may smoothly rotate inside the main frame 130.

[0071] The rotation shaft 125 may transfer rotational force of the drive motor 120 to the orbiting scroll 140 constituting the compression unit C. Accordingly, the orbiting scroll 140 eccentrically coupled to the rotation shaft 125 performs an orbiting motion with respect to the fixed scroll 150.

[0072] An oil passage 126 for guiding oil stored in the oil storage space S11 of the casing 110 to a sliding part may be defined inside the rotation shaft 125, and an oil pickup 127 for pumping up oil filled in the oil storage space S11 may be coupled to a lower end of the oil passage 126. Accordingly, the oil filled in the oil storage space S11 can be supplied to each sliding part while being suctioned up along the rotation shaft 125 through the oil pickup 127 and the oil passage 126 when the rotation shaft 125 rotates.

[0073] The oil passage 126 includes a first oil passage 1261 formed inside the rotation shaft 125 in the axial direction or an inclined direction, and a second oil passage 1261 extending from the first oil passage 1261 to penetrate through the outer circumferential surface of the rotation shaft 125.

[0074] As the compression unit 30 is located below the motor unit 120, the oil passage 1261 may be formed in a grooving manner from a lower end of the rotation shaft 125 to approximately a lower end or a middle height of the stator 121 or a position adjacent to an upper end of a main bearing portion 133 to be explained later. Of course, in some cases, the first oil passage 1261 may also be formed through the rotation shaft 125 in the axial direction.

[0075] The second oil passage 1262 may be provided in plurality to communicate with each sliding part, and the plurality of second oil passages 1262 may be formed at preset intervals along the axial direction to correspond to each sliding part.

[0076] The compression unit C according to the embodiment of the present invention includes a main frame 130, an orbiting scroll 140, and a fixed scroll 150. For example, the fixed scroll 150 may be disposed on a lower side of the main frame 130, the orbiting scroll 140 may be supported by the fixed scroll 150 in the axial direction to be orbitally movable between the main frame 130 and the fixed scroll 150.

[0077] Referring to FIG. 1, the orbiting scroll 130 includes a frame end plate portion 131, a frame side wall portion 132, and a main bearing portion 133. The frame end plate portion 131 is disposed beneath the drive motor 120. A main bearing hole 1331 that constitutes the main bearing portion 133 to be explained later is formed in the axial direction through the center of the frame end plate portion 131. The frame side wall portion 132 extends in a cylindrical shape from an edge of a lower surface of the frame end plate portion 131, to be fixed to the inner circumferential surface of the cylindrical shell 111 in a shrink-fitting or welding manner. The main bearing portion 133 is provided with the main bearing hole 1331 in which the rotation shaft 125 is rotatably inserted, so as to support the rotation shaft 125 in the radial direction.

[0078] Referring to FIG. 1, the orbiting scroll 140 includes an orbiting end plate portion 141, an orbiting wrap 142, and a rotation shaft coupling portion 143. The orbiting scroll 140 may be formed of a lighter material than the fixed scroll 150 to be described later, for example, a material having a coefficient of thermal expansion greater than that of the fixed scroll 150.

[0079] The orbiting end plate portion 141 is formed in a disk shape and accommodated in a portion between the frame end plate portion 131 and a fixed end plate portion 151 to be explained later. An upper surface of the orbiting end plate portion 141 may be supported in the axial direction by the main frame 130 with interposing a back pressure sealing member (no reference numeral given) therebetween.

[0080] An orbiting-side key groove 1411 is formed on one side surface of the orbiting end plate portion 141, that is, on an edge of the upper surface of the orbiting end plate portion 141 facing the main frame 130, to be recessed by a preset depth into an outer circumferential surface of the orbiting end plate portion 141. The orbiting-side key groove 1411 is formed long in the radial direction so that an orbiting-side key (not shown) of an Oldham ring 170 for suppressing rotation of the orbiting scroll 140 is slidably inserted. The depth of the orbiting-side key groove 1411 may be approximately half of a thickness of the orbiting end plate portion 141. Accordingly, when a first oil supply passage 1911, which will be described later, is formed on the same axis as the orbiting-side key groove 1411, it may be inappropriate because the first oil supply passage 1911 is supposed to be too small in inner diameter or the orbiting end plate portion 141 is supposed to be too thick in thickness.

[0081] In addition, on the edge of the orbiting end plate portion 141, that is, an outer surface of the orbiting end plate portion 141 facing the frame end plate portion 131 and the frame side wall portion 132, an intermediate pressure chamber Sm may be formed together with the frame end plate portion 131, the frame side wall portion 132, and a fixed side wall portion 152 to be explained later. The intermediate pressure chamber Sm communicates with the compression chamber V through an intermediate pressure passage 180 to be described later so as to form intermediate pressure (back pressure). Accordingly, the orbiting end plate portion 141 can be supported in the axial direction toward the fixed scroll 150 by receiving the back pressure of the intermediate pressure chamber Sm, thereby suppressing leakage between compression chambers V. The intermediate pressure chamber Sm and the intermediate pressure passage 180 will be described again later together with the fixed scroll 150.

[0082] Meanwhile, a first oil supply passage 191 is formed inside the orbiting end plate portion 141. The first oil supply passage 191 forms a portion of the oil supply passage 190 to be described later, and may be formed through the inside of the orbiting end plate portion 141. For example, one end of the first oil supply passage 191 may be open to an inner circumferential surface of the orbiting end plate portion 141 or to the upper surface of the orbiting end plate portion 141 facing the frame end plate portion 131 so as to communicate with the oil passage 126, and another end of the first oil supply passage 191 may be open to a lower surface of the orbiting end plate portion 141, that is, a thrust surface (hereinafter, first thrust surface) 140a of the orbiting scroll 140 so as to communicate directly with a second oil passage 192 to be described later. Accordingly, the first oil supply passage 191 may communicate with the second oil supply passage 192 without passing through the intermediate pressure chamber Sm. Then, a part of oil suctioned up from the inner space 110a of the casing 110 through the oil passage 126 of the rotation shaft 125 may flow directly to the second oil supply passage 192 through the first oil supply passage 191, and then may be supplied to the compression chamber V through the second oil supply passage 192. The first oil supply passage 191 will be described later along with the second oil supply passage 192 forming another portion of the oil supply passage 190.

[0083] The orbiting wrap 142 extends from the lower surface of the orbiting end plate portion 141 toward the fixed end plate portion 151 to be described later, and engages with a fixed wrap 154 to be described later to form the first compression chamber V1 and the second compression chamber V1.

[0084] The orbiting wrap 142 may be formed in an involute shape. However, the orbiting wrap 142 and the fixed wrap 154 may be formed in various shapes other than the involute shape. For example, the orbiting wrap 142 may be formed in a substantially elliptical shape in which a plurality of arcs having different diameters and origins are connected and the outermost curve may have a major axis and a minor axis. The fixed wrap 154 may also be formed in a similar manner. Hereinafter, this will be explained by defining it as a hybrid wrap shape.

[0085] An inner end portion of the orbiting wrap 142 may be formed at a central portion of the orbiting end plate portion 141, and the rotation shaft coupling portion 143 may be formed through the central portion of the orbiting end plate portion 141 in the axial direction. Accordingly, a discharge port 1511, which will be described later, is formed at an eccentric position from the center of the orbiting scroll 140, that is, the rotation shaft coupling portion 143.

[0086] An oil supply groove 195 which communicates with the second oil supply passage 192 to be described later is formed on an end surface of the orbiting wrap 142. The oil supply groove 195 is recessed by a preset depth along the axial direction of the orbiting wrap 142, and extends along a direction in which the orbiting wrap 142 is formed (or a direction in which the compression chamber is compressed). Accordingly, a portion of oil which is supplied to the compression chamber V through the oil supply passage 190 flows into the oil supply groove 195. This oil is diffused along the oil supply groove 195 to lubricate an area between the end surface 142a of the orbiting wrap 142 and one side surface of the fixed end plate portion 151 facing the end surface 142a. The oil supply groove 195 will be described later again together with the oil supply passage 190.

[0087] The rotation shaft 125 may be rotatably inserted into the rotation shaft coupling portion 143. An outer circumferential part of the rotation shaft coupling portion 143 may be connected to the orbiting wrap 142 to define the compression chamber V together with the fixed wrap 154 during a compression process.

[0088] The rotation shaft coupling portion 143 may be formed at a height at which it overlaps the orbiting wrap 142 on the same plane. That is, the rotation shaft coupling portion 143 may be disposed at a height at which an eccentric shaft portion 1251 of the rotation shaft 125 overlaps the orbiting wrap 142 on the same plane. Accordingly, repulsive force and compressive force of refrigerant can cancel each other while being applied to the same plane based on the orbiting end plate portion 141, and thus inclination of the orbiting scroll 140 due to the interaction between the compressive force and the repulsive force can be suppressed.

[0089] Referring to FIG. 1, the fixed scroll 150 may include a fixed end plate portion 151, a fixed side wall portion 152, a sub bearing portion 153, and a fixed wrap 154.

[0090] The fixed end plate portion 151 is formed in a disk shape and is disposed below the frame end plate portion 131 at a preset distance. A sub bearing hole 1531 that constitutes the sub bearing portion 153 is formed in the vertical direction through the center of the fixed end plate portion 151. Around the sub bearing hole 1531, a discharge port 1511 is formed adjacent to the sub bearing hole 1531. The discharge port 1511 communicates with each of the first compression chamber V1 and the second compression chamber V2 to be explained later, such that compressed refrigerant is discharged to a muffler space 160a of the discharge cover 160.

[0091] The discharge port 1511 is located at a position which is eccentric from the center of the fixed end plate portion 151. In other words, as the sub bearing hole 1531 is formed at the center of the fixed end plate portion 151, the discharge port 1511 is formed at a position eccentric from the sub bearing hole 1531.

[0092] The fixed side wall portion 152 extends in the vertical direction from an edge of an upper surface of the fixed end plate portion 151 to be coupled to the frame side wall portion 132 of the main frame 130. The fixed side wall portion 152 is provided with a suction port 1521 formed through the fixed side wall portion 152 in the radial direction. As aforementioned, an end portion of the refrigerant suction pipe 115 inserted through the cylindrical shell 111 is inserted into the suction port 1521.

[0093] In addition, an intermediate pressure passage 180 and the second oil supply passage 192 are formed at one side of the suction port 1521. In other words, the intermediate pressure passage 180 and the second oil supply passage 192 are formed at one side of the suction port 1521 in the circumferential direction. Accordingly, the intermediate pressure passage 180 and the second oil supply passage 192 may communicate with compression chambers V each having different pressure through the fixed side wall portion 152 without interference with the suction port 1521.

[0094] One end of the intermediate pressure passage 180 may communicate with the compression chamber V, and another end may communicate directly with the intermediate pressure chamber Sm to be described later. For example, one end of the intermediate pressure passage 180 communicates with the compression chamber V, which forms intermediate pressure between suction pressure and discharge pressure, among the compression chambers V, and another end of the intermediate pressure passage 180 may be formed sequentially through the fixed end plate portion 151 and the fixed side wall portion 152 to penetrate through an axial side surface of the fixed side wall portion 152, which forms the intermediate pressure chamber Sm to be described later, namely, a thrust surface (hereinafter, second thrust surface 150a) of the fixed scroll 150. Accordingly, the intermediate pressure chamber Sm can form appropriate back pressure according to pressure of the compression chamber V communicating with the intermediate pressure chamber Sm.

[0095] However, one end of the intermediate pressure passage 180 may communicate with a compression chamber V which has pressure higher than pressure of another compression chamber V, with which another end of the oil supply passage 190 to be described later, namely, another end of a third fixed oil supply portion 1923 defining an outlet of the oil supply passage 190 communicates. Accordingly, the intermediate pressure chamber Sm may form back pressure, which is sufficient to support the orbiting scroll 140 toward the fixed scroll 150, thereby stably sealing between the orbiting scroll 140 and the fixed scroll 150.

[0096] In addition, at least a portion of another end of the intermediate pressure passage 180 is formed to be located outside an orbiting radius range of the orbiting end plate portion 141 based on an orbiting angle of the orbiting scroll 140. For example, an intermediate pressure groove 180a extending radially from the second thrust surface 150a is formed on the another end of the intermediate pressure passage 180. The intermediate pressure groove 180a may be formed to be located outside the orbiting radius range of the orbiting end plate portion 141 at at least one point based on the rotation angle of the orbiting scroll 140. Accordingly, one end of the intermediate pressure passage 180 may continuously communicate with the compression chamber V while another end of the intermediate pressure passage 180 may continuously or / and temporarily communicate with the intermediate pressure chamber Sm. Then, as described above, the intermediate pressure chamber Sm can form appropriate back pressure according to the pressure of the compression chamber V.

[0097] On the other hand, the second oil supply passage 192 forms another part of the oil supply passage 190, and may be formed inside the fixed scroll 150, separated from the intermediate pressure passage 180 described above. For example, one end of the second oil supply passage 192 may be open to the upper surface of the fixed side wall portion 152, that is, the second thrust surface 150a of the fixed scroll 150 so as to communicate with the intermediate pressure chamber Sm. Another end of the second oil supply passage 192 may be open to the upper surface of the fixed end plate portion 151 so as to communicate with the compression chamber V. In other words, the one end of the second oil supply passage 192 may communicate with the another end of the first oil supply passage 191, and the another end of the second oil supply passage 192 may communicate with the compression chamber V at a rotation angle just after completion of suction in the compression chamber V, based on the rotation angle of the rotation shaft 125. Accordingly, the second oil supply passage 192 may communicate directly with the first oil supply passage 191 without passing through the intermediate pressure chamber Sm. Then, as described above, a part of oil suctioned up from the inner space 110a of the casing 110 through the oil passage 126 of the rotation shaft 125 may flow directly to the second oil supply passage 192 through the first oil supply passage 191, and then may be supplied to the compression chamber V through the second oil supply passage 192. The second oil supply passage 192 will be described later along with the first oil supply passage 191 forming another portion of the oil supply passage 190.

[0098] A sub bearing hole 1531 having a cylindrical shape may be formed through a center of the sub bearing portion 153 in the axial direction, and supports a lower end portion of the rotation shaft 125 in the radial direction.

[0099] A fixed wrap 154 may extend from the upper surface of the fixed end plate portion 151 toward the orbiting scroll 140 in the axial direction. The fixed wrap 154 is engaged with an orbiting wrap 142 to be described later to define the compression chamber V. The compression chamber V includes a first compression chamber V1 formed between an inner surface of the fixed wrap 154 and an outer surface of the orbiting wrap 142, and a second compression chamber V2 formed between an outer surface of the fixed wrap 154 and an inner surface of the orbiting wrap 142.

[0100] Since the fixed wrap 154 has a shape corresponding to the shape of the orbiting wrap 142 described above, a description of the fixed wrap 154 will be replaced with the description of the orbiting wrap 142.

[0101] In the drawings, an unexplained reference numeral 1512 denotes a bypass hole.

[0102] The scroll compressor according to the embodiment of the present invention may operate as follows.

[0103] That is, when power is applied to the driving motor 120, rotational force is generated and the rotor 122 and the rotation shaft 125 rotates accordingly. As the rotation shaft 125 rotates, the orbiting scroll 170 eccentrically coupled to the rotation shaft 125 performs an orbiting motion relative to the fixed scroll 150 by the Oldham ring 170.

[0104] Then, volumes of the first compression chamber V1 and the second compression chamber V2 gradually decrease toward the center from the outside of the respective compression chambers V1 and V2. Then, refrigerant is suctioned into the first compression chamber V1 and the second compression chamber V2 through the refrigerant suction pipe 115.

[0105] The refrigerant is then compressed while moving along a moving trajectory of each compression chamber V1 and V2. The compressed refrigerant flows into the muffler space 160a of the discharge cover 160 through the discharge port 1511 that communicates with the compression chamber.

[0106] The refrigerant is discharged to the discharge space S12 between the main frame 130 and the drive motor 120 through outflow holes (not shown) formed in the fixed scroll 150 and the main frame 130, passes through the drive motor 120, and moves to the upper space S2 of the casing 110 above the drive motor 120. The refrigerant is separated from oil in the upper space S2. The separated refrigerant exhausts to the outside of the casing 110 through the refrigerant discharge pipe 116 while the separated oil returns to the oil storage space S11 of the casing 110 through the oil return passage (no reference numeral given). The oil is supplied to each sliding part and the compression chamber V through the oil passage 126 of the rotation shaft 125 and then returned to the oil storage space S11 of the casing 110. Such series of processes are repeatedly performed.

[0107] On the other hand, when the orbiting wrap and the fixed wrap are formed in the existing involute shape, relatively wide margin areas where a compression chamber is not formed are left outside the outermost wraps of the orbiting wrap and the fixed wrap. In other words, in the existing involute wraps, the first thrust surface and the second thrust surface are formed to have wide areas. Therefore, in the existing involute wrap, a circular groove is formed wide on either the orbiting scroll or the fixed scroll, so that the oil supply passages of the both scrolls, that is, the oil supply passages connecting the inner space of the casing and the compression chamber continuously communicate with each other.

[0108] However, when the outermost wrap is expanded without an empty space as in the aforementioned hybrid wrap shape or elliptical wrap shape, the margin areas on the first thrust surface and the second thrust surface are narrowed. This makes it difficult to form the both oil supply passes to continuously communicate with each other. In consideration of this, in the case of the related art hybrid wrap shape as in Patent Document 1, the both oil supply passages are formed to continuously communicate with each other via the intermediate pressure chamber. This may increase volume efficiency by securing the maximum stroke volume, but increase a pressure difference between the inner space of the casing and the compression chamber, which is disadvantageous for an operation at a low-pressure ratio.

[0109] In other words, when the oil supply passages pass through the intermediate pressure chamber, pressure in the intermediate pressure chamber, that is, back pressure must be maintained appropriately. Accordingly, in the low-pressure ratio operation in which the operating pressure ratio is 1.3 or less, the pressure difference between the inner space of the casing and the compression chamber is not made. As a result, an oil supply by differential pressure is not smoothly performed. This may make it impossible to perform the low-pressure ratio operation in the scroll compressor and an air conditioner employing the same.

[0110] Therefore, non-circular oil supply portions may be formed in the orbiting scroll and the fixed scroll, respectively, so that the oil supply passage of the orbiting scroll and the oil supply passage of the fixed scroll continuously communicate with each other. Accordingly, the oil supply passages can directly communicate the inner space of the casing and the compression chamber without passing through the intermediate pressure chamber, which can allow an oil supply using differential pressure even at a low-pressure ratio that an operating pressure ratio is 1.3 or less, and further 1.1 or less.

[0111] FIG. 2 is an exploded perspective view of an orbiting scroll and a fixed scroll in FIG. 1, FIG. 3 is a planar view of the orbiting scroll in FIG. 2, FIG. 4 is a cross-sectional view taken along the line "IX-IX" of FIG. 3, FIG. 5 is a planar view of the fixed scroll in FIG. 2, and FIG. 6 is a cross-sectional view taken along line "X-X" of FIG. 5.

[0112] Referring to FIGS. 1 and 2, the orbiting scroll 140 has the first oil supply passage 191 constituting a part of the oil supply passage 190, and the fixed scroll 150 has the second oil supply passage 192 constituting another part of the oil supply passage 190. The first oil supply passage 191 and the second oil supply passage 192 communicate with each other to define one oil supply passage 190 as a single passage. Accordingly, some of oil suctioned from the inner space 110a of the casing 110 along the oil passage 126 of the rotation shaft 125 can be supplied to the compression chamber V through the oil supply passage 190.

[0113] Referring to FIGS. 2, 3, and 4, the first oil supply passage 191 includes a first orbiting oil supply part 1911, a second orbiting oil supply part 1912, and a third orbiting oil supply part 1913. The first orbiting oil supply part 1911 may be understood as an inlet of the first oil supply passage 191, the third orbiting oil supply part 1913 may be understood as an outlet of the first oil supply passage 191, and the second orbiting oil supply part 1912 may be understood as a connection part connecting the inlet and outlet of the first oil supply passage 191. However, another end of the second orbiting oil supply part 1912 to be described later may also be understood as the outlet of the first oil supply passage 191 together with the third orbiting oil supply part 1913.

[0114] The first orbiting oil supply part 1911 may be recessed from the inside of the orbiting end plate portion 141 toward the outer circumferential surface by a preset depth. One end of the first orbiting oil supply part 1911 may extend from an inner circumferential surface of the orbiting end plate portion 141, that is, from an inner circumferential surface of the rotation shaft coupling portion 143 toward an outer circumferential surface of the orbiting end plate portion 141. Or, the one end of the first orbiting oil supply part 1911 may extend toward the outer circumferential surface of the orbiting end plate portion 141 from a groove, which is recessed by a preset depth from an upper surface of the orbiting end plate portion 141 at an inner circumferential side thereof, facing the frame end plate portion 131. Hereinafter, a description will be given of an example in which the first orbiting oil supply part 1911 extends from the upper surface of the inner circumferential side of the orbiting end plate portion 141 toward the outer circumferential surface, but for convenience, the description will be given as the first orbiting oil supply part 1911 extends from the inner to outer circumferential surfaces of the orbiting end plate portion 141.

[0115] Specifically, one end of the first orbiting oil supply part 1911 may be open to the inner circumferential surface of the orbiting scroll 140 (precisely, the upper surface of the inner circumferential side), and the another end of the first orbiting oil supply part 1911 may extend toward the outer circumferential surface of the orbiting scroll 140 in a transverse direction (which may be understood as a radial direction for convenience). However, the one end of the first orbiting oil supply part 1911 may be formed through the inner circumferential surface of the orbiting scroll 140 so as to communicate with the oil passage 126 of the rotation shaft 125, while the another end of the first orbiting oil supply part 1911 may be closed by a separate stopper member (no reference numeral given) even if the another end is formed through the outer circumferential surface of the orbiting scroll 140. Accordingly, the another end of the first orbiting oil supply part 1911 may be blocked with respect to the intermediate pressure chamber Sm without communicating with the intermediate pressure chamber Sm.

[0116] In addition, when projected in the axial direction, the first orbiting oil supply part 1911 may be formed at a position where it does not interfere with the orbiting-side key groove 1411 of the Oldham ring 170 disposed on one side surface of the orbiting end plate portion 141, in other words, at one side of the orbiting-side key groove 1411 in the circumferential direction with a preset interval. Accordingly, the first orbiting oil supply part 1911 can be suppressed from interfering with the orbiting-side key groove 1411. This may result in forming the first orbiting oil supply part 1911 in the middle of the orbiting end plate portion 141 while maintaining the orbiting end plate 141 to be thin in thickness.

[0117] In addition, an inner diameter D11 of the first orbiting oil supply part 1911 may be larger than an inner diameter D12 of the second orbiting oil supply part 1912 to be explained later. Accordingly, the first orbiting oil supply part 1911 can be easily machined to have a length longer than a length of the second orbiting oil supply part 1912.

[0118] Although not shown in the drawings, a pressure reducing member (not shown) may be inserted into the first orbiting oil supply part 1911. This can increase the inner diameter D11 of the first orbiting oil supply part 1911 and simultaneously enhance a decompression effect in the first orbiting oil supply part 1911, thereby lowering pressure of oil introduced into the compression chamber V to appropriate pressure.

[0119] The second orbiting oil supply part 1912 may communicate with the first orbiting oil supply part 1911 and may penetrate through the orbiting end plate portion 141 in the longitudinal direction toward the fixed scroll 150.

[0120] Specifically, one end of the second orbiting oil supply part 1912 may communicate with the first orbiting oil supply part 1911, and another end of the second orbiting oil supply part 1912 may extend toward the fixed scroll 150 in the axial direction to penetrate through the orbiting end plate portion 141. For example, the one end of the second orbiting oil supply part 1912 may communicate with the first orbiting oil supply part 1911, and the another end of the second orbiting oil supply part 1912 may be formed through the lower surface of the orbiting end plate portion 141 defining the thrust surface (i.e., the first thrust surface) 140a of the orbiting scroll 140. Accordingly, the second orbiting oil supply part 1912 may be open toward the first thrust surface 140a at a position without overlapping the compression chamber V.

[0121] In addition, the inner diameter D12 of the second orbiting oil supply part 1912 may be smaller than the inner diameter D11 of the first orbiting oil supply part 1911. In other words, the length of the second orbiting oil supply part 1912 may be shorter than the length of the first orbiting oil supply part 1911, but the inner diameter D12 of the second orbiting oil supply part 1912 may be smaller than the inner diameter D11 of the first orbiting oil supply part 1911. This can enhance a decompression effect in the second orbiting oil supply part 1912, thereby lowering pressure of oil introduced into the compression chamber V to appropriate pressure.

[0122] Referring to FIGS. 2 and 3, the third orbiting oil supply part 1913 may communicate with the second orbiting oil supply part 1912 and extend in the transverse direction from the first thrust surface 140a, which is the lower surface of the orbiting end plate portion 141.

[0123] Specifically, the third orbiting oil supply part 1913 may extend in the circumferential direction from the another end of the second orbiting oil supply part 1912 facing the fixed scroll 150. In other words, the third orbiting oil supply part 1913 may be formed in a non-circular cross-sectional shape when projected in the axial direction, and may be formed as a groove that is recessed by a preset depth from the lower surface of the orbiting end plate portion 141 constituting the first thrust surface 140a. For example, one end of the third orbiting oil supply part 1913 may communicate with the another end of the second orbiting oil supply part 1912, and another end of the third orbiting oil supply part 1913 may extend in the circumferential direction to communicate with the third fixed oil supply part 1923 of the second oil supply passage 192 to be described later.

[0124] In addition, the third orbiting oil supply part 1913 may extend up to a position where it overlaps the orbiting-side key groove 1511 in the axial direction when projected in the axial direction. However, the third orbiting oil supply part 1913 may be formed by a depth that is not enough to communicate with the orbiting-side key groove 1511. Accordingly, while the third orbiting oil supply part 1913 can extend up to a position as close as possible to the second oil supply passage 192 to be described later, the first oil supply passage 191 can be suppressed from communicating with the intermediate pressure chamber Sm through the orbiting-side key groove 1511.

[0125] In addition, a width D13 of the third orbiting oil supply part 1913 may be smaller than or equal to the inner diameter D12 of the second orbiting oil supply part 1912. In other words, the width D13 between both ends of the third orbiting oil supply part 1913 may be constant, but may be smaller than or equal to the inner diameter D12 of the second orbiting oil supply part 1912. This embodiment illustrates an example in which the width D13 of the third orbiting oil supply part 1913 is the same as the inner diameter D12 of the second orbiting oil supply part 1912. Accordingly, the oil supply passage 190 can be secured in the relatively narrow first thrust surface 140a of the orbiting scroll 140, and simultaneously a sealing distance between the oil supply passage 190 and the outer circumferential surface of the orbiting end plate portion 141 can be secured.

[0126] On the other hand, referring to FIGS. 2, 5, and 6, the second oil supply passage 192 includes a first fixed oil supply part 1921, a second fixed oil supply part 1923, a third fixed oil supply part 1923, and a fourth fixed oil supply part 1924. The first fixed oil supply part 1921 may be understood as an inlet of the second oil supply passage 192 together with the fourth fixed oil supply part 1924, the third fixed oil supply part 1923 may be understood as an outlet of the second oil supply passage 192, and the second fixed oil supply part 1922 may be understood as a connection part connecting the inlet and outlet of the second oil supply passage 192.

[0127] The first fixed oil supply part 1921 may be recessed from the fixed side wall portion 152 by a preset depth in the longitudinal direction.

[0128] Specifically, one end of the first fixed oil supply part 1921 may be open toward the thrust surface (i.e., the second thrust surface) 150a of the fixed scroll 150 facing the thrust surface 140a of the orbiting scroll 140, and another end of the first fixed oil supply part 1921 may extend toward another side surface of the fixed scroll 150, that is, a lower surface of the fixed side wall portion 152, which is opposite to the second thrust surface 150a in the longitudinal direction (which may be understood as the axial direction for convenience). However, the first fixed oil supply part 1921 may be formed as a groove having a preset depth in the second thrust surface 150a along the axial direction, or may be formed through the fixed side wall portion 152 but the lower surface may be covered using a separate stopper. This embodiment illustrates an example in which the first fixed oil supply part 1921 is recessed by a preset depth from the second thrust surface 150a.

[0129] In addition, the one end of the first fixed oil supply part 1921 may be formed at a position where it is always covered by the lower surface of the orbiting end plate portion 141, that is, the first thrust surface 140a. For example, the one end of the first fixed oil supply part 1921 may be formed in an orbiting trajectory range of the orbiting end plate portion 141. Accordingly, as the one end of the first fixed oil supply part 1921 is formed at a position where it overlaps the orbiting end plate portion 141 in the axial direction during the orbiting motion of the orbiting end plate portion 141, the one end of the first fixed oil supply part 1921, similar to the another end of the first orbiting oil supply part 1911, may be blocked from the intermediate pressure chamber Sm without communicating with the intermediate pressure chamber Sm.

[0130] In addition, an inner diameter D21 of the first fixed oil supply part 1921 may be smaller than a width D24 of the fourth fixed oil supply part 1924 to be explained later. Accordingly, the first fixed oil supply part 1921 can be formed in the fixed side wall portion 152 without interfering with an adjacent component such as a capacity-variable bypass hole 1512, and a decompression effect in the first fixed oil supply part 1921 can be enhanced, thereby lowering pressure of oil introduced into the compression chamber V to appropriate pressure.

[0131] Although not shown in the drawings, a pressure reducing member (not shown) may be inserted into the first fixed oil supply part 1921. This can increase an inner diameter D21 of the first fixed oil supply part 1921 as wide as possible in a range without interference with an adjacent component, and simultaneously enhance the decompression effect in the first fixed oil supply part 1921, thereby lowering pressure of oil introduced into the compression chamber V to appropriate pressure.

[0132] The second fixed oil supply part 1922 may communicate with the first fixed oil supply part 1921 and may be recessed by a preset depth in the transverse direction.

[0133] Specifically, one end of the second fixed oil supply part 1922 may communicate with the first fixed oil supply part 1921 and another end of the second fixed oil supply part 1922 may extend toward the compression chamber V in the transverse direction (which may be understood as the radial direction for convenience). For example, the one end of the second fixed oil supply part 1922 may be formed through the outer circumferential surface of the fixed scroll 150, and the another end of the second fixed oil supply part 1922 may extend by a preset depth by continuously grooving the fixed side wall portion 152 and the fixed end plate portion 151. In this case, the one end of the second fixed oil supply part 1922 may be sealed using a separate stopper member (no reference numeral given), and the another end of the second fixed oil supply part 1922 may be formed in a closed shape by being grooved up to the middle of the fixed end plate portion 151. Accordingly, both ends of the second fixed oil supply part 1922 may be blocked.

[0134] In addition, the second fixed oil supply part 1922 is formed in the transverse direction, and may be formed in a direction inclined with respect to the axial center O. Accordingly, the second oil supply passage 192 including the second fixed oil supply part 1922 can communicate with the compression chamber V by avoiding a fastening hole 1522 formed through the fixed side wall portion 152 as well as a bypass hole 1512 formed through the fixed end plate portion 151.

[0135] In addition, an inner diameter of the second fixed oil supply part 1922 may be smaller than a width D24 of the fourth fixed oil supply part 1924 to be explained later. Accordingly, the second fixed oil supply part 1922 can be formed in the fixed side wall part 152 without interfering with an adjacent component such as a capacity-variable bypass hole 1512, and a decompression effect in the first fixed oil supply part 1921 can be enhanced, thereby lowering pressure of oil introduced into the compression chamber V to appropriate pressure.

[0136] Although not shown in the drawings, a pressure reducing member (not shown) may be inserted into the second fixed oil supply part 1922. This can increase the inner diameter of the second fixed oil supply part 1922 as wide as possible in a range without interference with an adjacent component, and simultaneously enhance the decompression effect in the second fixed oil supply part 1922, thereby lowering pressure of oil introduced into the compression chamber V to appropriate pressure.

[0137] The third fixed oil supply part 1923 may be formed through the inside of the fixed end plate portion 151 in the longitudinal direction to communicate with the compression chamber V via the second fixed oil supply part 1922.

[0138] Specifically, one end of the third fixed oil supply part 1923 may communicate with the another end of the second fixed oil supply part 1922, and another end of the third fixed oil supply part 1923 may be formed through the upper surface of the fixed end plate portion 151 forming the compression chamber V, to communicate with the compression chamber V. Accordingly, the first oil supply passage 191 communicating with the oil passage 126 of the rotation shaft 125 can be connected to the compression chamber V through the second oil supply passage 192.

[0139] The another end of the third fixed oil supply part 1923 constituting the outlet of the second oil supply passage 192 may communicate with the compression chamber V as described above, but the communication with the compression chamber V may be made immediately after a time point that compression is started after completion of suction, namely, immediately after arriving at a suction completion angle or / and a compression start angle, for example, within a range of 10 ° to 20 ° after the suction completion angle or / and compression start angle α. Accordingly, even in a low-pressure ratio operation in which a compression ratio is 1.1 or less, oil stored in the oil storage space S11 of the casing 110 can be smoothly introduced into the compression chamber V.

[0140] However, the another end of the intermediate pressure passage 1923, as described above, may communicate with the compression chamber V which has pressure higher than pressure of another compression chamber V, which communicate with one end of the intermediate pressure passage 180 defining the inlet of the intermediate pressure passage 180. Accordingly, a great pressure difference can be generated between the inner space 110a of the casing 110 and the compression chamber V, which may result in smoothly supplying oil stored in the inner space 110a of the casing 110 into the compression chamber V even during the low-pressure ratio operation.

[0141] In addition, the another end of the third fixed oil supply part 1923 may be formed in the middle between the outermost fixed wrap 154 and the fixed wrap 154 facing the outermost fixed wrap in the radial direction, and an inner diameter D23 of the third fixed oil supply part 1923 may be smaller than a wrap thickness of the orbiting wrap 142. Accordingly, during the orbiting motion of the orbiting wrap 142, the another end of the third fixed oil supply part 1923 can alternately communicate with both compression chambers V, so that oil can be evenly supplied into both of the compression chambers V.

[0142] In addition, the inner diameter D23 of the third fixed oil supply part 1923 may be smaller than a width D24 of the fourth fixed oil supply part 1924 to be explained later. Accordingly, the second fixed oil supply part 1922 can be formed in the fixed side wall part 152 without interfering with the adjacent component such as the capacity-variable bypass hole 1512, and the decompression effect in the first fixed oil supply part 1921 can be enhanced, thereby lowering pressure of oil introduced into the compression chamber to appropriate pressure.

[0143] Referring to FIGS. 2 and 5, the fourth fixed oil supply part 1924 may be formed in the second thrust surface 150a of the fixed scroll 150 by communicating with the one end of the first fixed oil supply part 1921.

[0144] Specifically, the fourth fixed oil supply part 1924 may communicate with the one end of the first fixed oil supply part 1921 facing the orbiting scroll 140, and may be formed in the shape of a groove having a preset depth in the second thrust surface 150a which defines the upper surface of the fixed side wall portion 152. Accordingly, the fourth fixed oil supply part 1924 can communicate with the third orbiting oil supply part 1913 constituting the first oil supply passage 191.

[0145] In addition, the fourth fixed oil supply part 1924 may be formed in a non-circular cross-sectional shape when projected in the axial direction, and a width D24 of the fourth fixed oil supply part 1924 may be larger than the inner diameter D21 of the first fixed oil supply part 1921. For example, the fourth fixed oil supply part 1924 may extend long along the fixed wrap 154 in a first transverse direction, which is substantially similar to a forming direction (or circumferential direction) of the fixed wrap 154, and a length (second transverse length) L22 in a second transverse direction which is substantially orthogonal to the first transverse direction may be shorter than a first transverse length L21 but larger than the inner diameter D21 of the first fixed oil supply part 1921. Accordingly, the width (or cross-sectional area) D24 of the fourth fixed oil supply part 1924 may be larger than the inner diameter (or cross-sectional area) D21 of the first fixed oil supply part 1921, such that the second oil supply passage 192 including the fourth fixed oil supply part 1924 can continuously communicate with the first oil supply passage 191 including the third orbiting oil supply part 1913 without interruption.

[0146] In addition, the fourth fixed oil supply part 1924 may be formed such that a cross-sectional area at a side away from the first fixed oil supply part 1921 is larger than a cross-sectional area at a side adjacent to the first fixed oil supply part 1921. Accordingly, even in the second thrust surface 150a of the fixed scroll 140, the fourth fixed oil supply part 1924 can be formed wide on a relative wide side and simultaneously can be formed to have a size as large as possible. This can be more advantageous in view of allowing the second oil supply passage 192 to continuously communicate with the first oil supply passage 191.

[0147] In addition, the width D24 of the fourth fixed oil supply part 1924 may be larger than a width D13 of the third orbiting oil supply part 1913 constituting the first oil supply passage 191. In other words, the second thrust surface 150a of the fixed scroll 150 may have a relatively large margin area considering a sealing distance, compared to the first thrust surface 140a of the orbiting scroll 140. Therefore, the width D24 of the fourth fixed oil supply part 1924 may be larger than the width of the third orbiting oil supply part 1913. Accordingly, even if the width D13 of the third orbiting oil supply part 1913 disposed in the first thrust surface 140a of the orbiting end plate portion 141 is smaller than the inner diameter D11 of the first orbiting oil supply part 1911, since the width D24 of the fourth fixed oil supply part 1924 is larger than the width D13 of the third orbiting oil supply part 1913, the third orbiting oil supply part 1913 can continuously communicate with the fourth fixed oil supply part 1924 without interruption.

[0148] FIG. 7 is a schematic view of a state, in which the orbiting scroll and the fixed scroll are coupled, viewed from the side of the fixed scroll, and FIG. 8 is an enlarged schematic view of the relationship between a third orbiting oil supply part and a fourth fixed oil supply part according to the change in rotation angle in FIG. 7.

[0149] Referring to FIG. 7, as described above, as the first oil supply passage 191 is directly connected to the second oil supply passage 192 without passing through the intermediate pressure chamber Sm, oil stored in the oil storage space S11 of the casing 110 is supplied directly to the compression chamber V through the first oil supply passage 191 and the second oil supply passage 192.

[0150] At this time, as the third orbiting oil supply part 1913 constituting the portion of the first oil supply passage 191 is formed in the first thrust surface 140a of the orbiting scroll 140, the third orbiting oil supply part 1913 performs an orbiting motion relative to the fourth fixed oil supply part 1924 constituting the portion of the second oil supply passage 192 during the orbiting motion of the orbiting end plate portion 141. Accordingly, the third orbiting oil supply part 1913 and the fourth fixed oil supply part 1924 may be spaced apart from each other depending on the shape or formation position.

[0151] However, as described above, the third orbiting oil supply part 1913 extends long along the circumferential direction, and the fourth fixed oil supply part 1924 extends long in the circumferential direction like the third orbiting oil supply part 1913 and is also formed wide in the radial direction, so as to be located at a position overlapping the third orbiting oil supply part 1913 in the axial direction. Then, even if the third orbiting oil supply part 1913 makes an orbiting motion, at least a portion of the third orbiting oil supply part 1913 is located within a formation range of the fourth fixed oil supply part 1924.

[0152] Then, as illustrated in FIG. 8, the third orbiting oil supply part 1913 and the fourth fixed oil supply part 1924 are continuously connected without interruption. The oil stored in the oil storage space S11 of the casing 110 can thus be supplied to both of the compression chambers V1 and V2 through the oil supply passage 190, which alternately communicates with the both compression chambers V1 and V2 without passing through the intermediate pressure chamber Sm. Accordingly, even in a low-pressure ratio operation in which the difference between pressure in the inner space 110a of the casing 110 and pressure in the compression chamber V is 1.3 or less, and furthermore, 1.1 or less, an oil supply into the compression chamber using differential pressure can be performed. This can allow the low-pressure ratio operation in a scroll compressor having a hybrid-wrap and an air conditioner having the same, resulting in enhancing efficiencies of the scroll compressor and the air conditioner.

[0153] As explained above, in a scroll compressor using a differential pressure oil supply method, the temperature of a suction-side wrap rapidly increases under abnormal operating conditions, such as rapid starting, which may cause excessive thermal expansion of a suction-side of an orbiting wrap, which has a relatively great coefficient of thermal expansion. This thermal expansion may significantly increase friction loss and / or wear between an end surface of the orbiting wrap and a fixed end plate portion facing the end surface, thereby reducing compression efficiency and reliability.

[0154] Accordingly, an oil supply groove communicating with an oil supply passage may be formed in a suction-side end surface of an orbiting wrap, such that oil supplied to a compression chamber through the oil supply passage can be partially supplied to the suction-side end surface of the orbiting wrap. Accordingly, oil can be continuously supplied to a gap between the suction-side end surface of the orbiting wrap and the fixed end plate portion facing the end surface, thereby suppressing damage to the suction-side end surface of the orbiting wrap even under abnormal operating conditions, such as rapid starting.

[0155] FIG. 9 is a planar view of a state, in which the orbiting scroll and the fixed scroll are coupled, viewed from the side of the orbiting scroll, and FIG. 10 is a schematic view of a communication relationship between an oil supply passage and an oil supply groove in FIG. 9.

[0156] Referring back to FIGS. 1 and 2, the oil supply groove 195 is recessed by a preset depth in a wrap height direction into the end surface 142a of the orbiting wrap 142 facing the fixed end plate portion 151. For example, the oil supply groove 195 may have a depth which is half or less of a wrap height. This may suppress deterioration of wrap rigidity due to the oil supply groove 195.

[0157] The oil supply groove 195 may be formed to communicate with the second oil supply passage 192. For example, the oil supply groove 195 may be formed to periodically and / or continuously communicate with a third fixed oil supply part 1923, which forms an outlet of the second oil supply passage 192.An example is shown in which the oil supply groove 195 periodically communicates with the third fixed oil supply part 1923. As shown in FIG. 9, an inner diameter D23 of the third fixed oil supply part 1923 may be smaller than a wrap thickness T1 of the orbiting wrap 142, and a width D5 of the oil supply groove 195 may be smaller than or equal to the inner diameter D23 of the third fixed oil supply part 1923. This may suppress the third fixed oil supply part 1923 from simultaneously communicating with both compression chambers V1 and V2, and secure as wide as possible a width D6 of each of opposite side end surfaces 142a1 of the orbiting wrap 142, which are located on opposite sides of the oil supply groove 195 in a widthwise direction, thereby suppressing damage to the orbiting wrap 142.

[0158] The oil supply groove 195 may extend along the formation direction of the orbiting wrap 142, but may be formed in a range, which includes a suction completion angle based on a rotation angle of the rotation shaft 125, from the outer end (suction-side end) of the orbiting wrap 142. In another example, as shown in FIGS. 9 and 10, the oil supply groove 195 may be formed in an arcuate shape when projected in the axial direction, but a first end 195a of the oil supply groove 195 may be spaced apart from the outer end of the orbiting wrap 142 by a sealing length L5, and a second end 195b may be formed at a position forming an angle of approximately 300° or less from the outer end (suction-side end) of the orbiting wrap 142, for example, an angle of approximately 270° to be located on the same axis as the third fixed oil supply part 1923 while the orbiting scroll 140 and the fixed scroll 150 are aligned with each other. For example, the second end 195b of the oil supply groove 195 may be formed such that one end of the third fixed oil supply part 1923 is located in an orbiting range of the oil supply groove 195. Accordingly, the oil supply groove 195 may communicate with the second oil supply passage 192 at least once per pivoting of the orbiting scroll 140, for example, per rotation of the rotation shaft 125, during the orbiting motion of the orbiting scroll 140, so that some of oil supplied to the compression chamber V through the oil supply passage 190 can flow into the oil supply groove 195.

[0159] The oil supply groove 195 may be formed with the same cross-sectional area along the formation direction of the orbiting wrap 142. In another example, the oil supply groove 195 may be formed to have the same width D5 and / or depth (reference numeral not given) along the formation direction of the orbiting wrap 142. Accordingly, an amount of oil received in the oil supply groove 195 may be maintained uniformly while easily forming the oil supply groove 195.

[0160] The oil supply groove 195 may be formed to be symmetrical in the widthwise direction with respect to the center line of the orbiting wrap 142. For example, the side end surfaces 142a1 on opposite sides of the orbiting wrap 142 based on the oil supply groove 195 may have the same width D6. Accordingly, the friction loss and / or wear on the end surface 142a of the orbiting wrap 142 may be further reduced and the reliability may be further increased.

[0161] In case that the oil supply groove 195 is formed in the suction-side end surface (or outer-side end surface) 142a of the orbiting wrap 142 to communicate with the second oil supply passage 192, some of oil supplied to the compression chamber V through the oil supply passage 190 may flow into the oil supply groove 195.

[0162] The oil may spread along the formation direction of the oil supply groove 195 and lubricate a gap between the suction-side end surface 142a of the orbiting wrap 142 made of a material with a relatively high coefficient of thermal expansion and one side surface of the fixed end plate portion 151 facing the suction-side end surface 142a.

[0163] Then, even if the temperature of the compression unit C rises significantly due to friction between the wraps under abnormal operating conditions, such as rapid starting, and the deformation of the suction-side wrap of the orbiting wrap 142 increases significantly, the friction loss and / or wear between the suction-side end surface 142a of the orbiting wrap 142 and the one side surface of the fixed end plate portion 151 facing the suction-side end surface 142a may be reduced.

[0164] In this way, when the orbiting scroll is manufactured from a material having a higher coefficient of thermal expansion than that of the fixed scroll, even when abnormal operating conditions, such as rapid starting, occur, friction loss and / or wear between the suction-side end surface of the orbiting scroll and the fixed end plate portion may be suppressed, thereby improving the compression efficiency and / or reliability of the scroll compressor in which the orbiting scroll is manufactured from the material having the higher coefficient of thermal expansion than that of the fixed scroll.

[0165] Hereinafter, a description will be given of another example of the oil supply groove.

[0166] For example, the cross-sectional area of the oil supply groove is formed equally along the formation direction of the orbiting wrap, but in some cases, the cross-sectional area of the oil supply groove may be formed differently along the formation direction of the orbiting wrap.

[0167] FIG. 11 is a planar view of an orbiting scroll to explain another example of an oil supply groove.

[0168] Referring to FIG. 11, the basic configuration and the resulting operational effects of the oil supply passage and the oil supply groove 195 according to this example are similar to those of the example of FIG. 9 described above, and therefore, a description thereof will be replaced with the description of the example of FIG. 9.

[0169] However, the oil supply groove 195 may include a first oil supply groove 1951 and a second oil supply groove 1952. The first oil supply groove 1951 may be a portion which directly communicates with an outlet of the second oil supply passage 192, for example, the third fixed oil supply part 1923, and the second oil supply groove 1952 may be a portion which indirectly communicates with the third fixed oil supply part 1923 through the first oil supply groove 1951. Accordingly, the second oil supply groove 1951 and the second oil supply groove 1952 may be formed to communicate with each other.

[0170] The first oil supply groove 1951 may be formed in an arcuate shape, but may be formed to have a first cross-sectional area which is uniform along the formation direction of the orbiting wrap 142. Accordingly, in a section where the first oil supply groove 1951 is formed, the width D6 of the side end surface 142a1 of the orbiting wrap 142 excluding the first oil supply groove 1951 may be maintained uniformly, thereby reducing the friction loss and / or wear and increasing reliability with respect to the end surface 142a of the orbiting wrap 142.

[0171] In this case, the first oil supply groove 1951 may be formed to be symmetrical in the widthwise direction with respect to the center line of the orbiting wrap 142. Accordingly, the side end surfaces 142a1 on the opposite sides of the orbiting wrap 142 based on the first oil supply groove 1951 may be formed have the same width, thereby further reducing the friction loss and / or wear on the end surface 142a of the orbiting wrap 142 and further increasing the reliability.

[0172] The second oil supply groove 1952 may be formed in an arcuate shape, but may be formed to have a second cross-sectional area which is uniform along the formation direction of the orbiting wrap 142. For example, the second oil supply groove 1952 may have the same depth as the first oil supply groove 1951, but a width D52 of the second oil supply groove 1952 may be larger than a width D51 of the first oil supply groove 1951. Accordingly, an amount of oil stored in the second oil supply groove 1952 may become larger than an amount of oil stored in the first oil supply groove 1951. Therefore, in a section where the second oil supply groove 1952 is formed, the width D6 of the side end surface 142a1 of the orbiting wrap 142 excluding the second oil supply groove 1952 may be maintained uniformly, thereby reducing the friction loss and / or wear and increasing reliability with respect to the end surface 142a of the orbiting wrap 142.

[0173] In this case, the cross-sectional area of the second oil supply groove 1952 may be larger than the cross-sectional area of the first oil supply groove 1951, but the second oil supply groove 1952 may be expanded by the same width in both width directions relative to the first oil supply groove 1951. As the second oil supply groove 1952 is expanded more than the first oil supply groove 1951 and the side end surfaces 142a1 on the opposite sides of the orbiting wrap 142 have the same width D6 based on the second oil supply groove 1952, the friction loss and / or wear with respect to the end surface 142a of the orbiting wrap 142 may be further reduced and the reliability may be further increased.

[0174] As described above, when the cross-sectional area of the second oil supply groove 1952 is larger than that of the first oil supply groove 1951, an amount of oil to be supplied to a portion, on which a relatively large wrap deformation occurs, may increase, thereby further reducing the friction loss and / or wear between the end surface 142a of the orbiting wrap 142 and the fixed end plate portion 151 facing the end surface 142a, and further enhancing the reliability.

[0175] Although not shown, the width D52 of the second oil supply groove 1952 and the width D51 of the first oil supply groove 1951 may be formed to be the same, and the depth of the second oil supply groove 1952 may be formed to be larger than the depth of the first oil supply groove 1951. Accordingly, while the amount of oil stored in the second oil supply groove 1952 is larger than that stored in the first oil supply groove 1951, the widths of the opposite end surfaces in the section where the second oil supply groove 1952 is formed may be the same as the widths of the opposite side end surfaces 142a1 in the section where the first oil supply groove 1951 is formed. This may increase the lubrication effect in the second oil supply groove 1952 while enhancing the reliability of the orbiting wrap 142.

[0176] Hereinafter, a description will be given of still another example of the oil supply groove.

[0177] For example, in FIG. 10, the cross-sectional area of the second oil supply groove is larger than the cross-sectional area of the second oil supply groove, but in some cases, the cross-sectional area of the second oil supply groove may be smaller than the cross-sectional area of the second oil supply groove.

[0178] FIG. 12 is a planar view of an orbiting scroll to explain another example of an oil supply groove.

[0179] Referring to FIG. 12, the basic configuration and the resulting operational effects of the oil supply passage 190 and the oil supply groove 195 according to this example are similar to those of the example of FIG. 9 and the example of FIG. 11 described above, and therefore, a description thereof will be replaced with the descriptions of the example of FIG. 9 and the example of FIG. 11. For example, the oil supply groove 195 may have a cross-sectional area which differs along the formation direction of the orbiting wrap 142 as in the example of FIG. 11.

[0180] However, the oil supply groove 195 may include the first oil supply groove 1951 and the second oil supply groove 1952, but the cross-sectional area of the second oil supply groove 1952 may be smaller than the cross-sectional area of the first oil supply groove 1951. For example, the inner diameter D52 of the second oil supply groove 1952 may be smaller than the width D51 of the first oil supply groove 1951. Accordingly, the width D6 of the side end surface 142a1 of the orbiting wrap 142 excluding the second oil supply groove 1952 in the section where the second oil supply groove 1952 is formed may be larger than the width D5 of the side end surface 142a1 of the orbiting wrap 142 excluding the first oil supply groove 1951 in the section where the first oil supply groove 1951 is formed.

[0181] As described above, when the cross-sectional area of the second oil supply groove 1952 is smaller than that of the first oil supply groove 1951, the side end surface 152a1 of the orbiting wrap in the section where the second oil supply groove 1952 is formed may be smoothly lubricated through the second oil supply groove 1952 while enhancing reliability of the orbiting wrap 152 in a section where a relatively great thermal deformation occurs.

[0182] Although not shown, the width D52 of the second oil supply groove 1952 and the width D51 of the first oil supply groove 1951 may be formed to be the same, and the depth of the second oil supply groove 1952 may be formed to be smaller than the depth of the first oil supply groove 1951. Accordingly, since the height of the end surface in the section where the second oil supply groove 1952 is formed is lower than the height of the end surface in the section where the first oil supply groove 1951 is formed, such that wrap rigidity in the section where the second oil supply groove 1952 is formed may be more improved than wrap rigidity in the section where the first oil supply groove 1951 is formed. This may result in securing the lubrication effect in the second oil supply groove 1952, in which a relatively great thermal deformation occurs, while enhancing the reliability of the orbiting wrap 142.

Claims

1. A scroll compressor comprising: a casing (110) in which a certain amount of oil is stored; a rotation shaft (125) arranged in an inner space (110a) of the casing (110) and having an oil passage (126) therein; an orbiting scroll (140) comprising an orbiting end plate portion (141) coupled to the rotation shaft (125) to perform an orbiting motion, and an orbiting wrap (142) arranged on one side surface of the orbiting end plate portion (141); a fixed scroll (150) comprising a fixed wrap (154) arranged on one side surface of the fixed end plate portion (151) and engaged with the orbiting wrap (154) to form a compression chamber (V, V1, V2); a main frame (130) fixed to the inner space (110a) of the casing (110), and forming an intermediate pressure chamber (Sm) together with the orbiting scroll (140) and the fixed scroll (150) to press the orbiting scroll (140) toward the fixed scroll (150); an oil supply groove (195) is formed in an end surface (142a) of the orbiting wrap (142) facing the fixed end plate portion (151) to communicate with the oil supply passage (190), wherein the oil supply groove (195) is recessed by a preset depth along a height direction of the wrap (154) and extends along a formation direction of the wrap (154), characterized by further comprising: an oil supply passage (190) comprising: a first oil supply passage (191) arranged in the orbiting scroll (140) and having one end communicating with the oil passage (126) of the rotation shaft (125); and a second oil supply passage (192) arranged in the fixed scroll (150) and having one end communicating with the first oil supply passage (191) and another end communicating with the compression chamber (V, V1, V2), wherein the oil supply passage (190) is isolated from the intermediate pressure chamber (Sm) and allows the oil passage (126) to communicate with the compression chamber (V, V1, V2).

2. The scroll compressor of claim 1, wherein the oil supply groove (195) is formed in a range of a rotation angle of 300° of the rotation shaft (125) inwardly along a formation direction of the orbiting wrap (140) from a point, which is spaced by a preset sealing length apart from an outer end of the orbiting wrap (142).

3. The scroll compressor of claim 1 or 2, wherein one end of the oil supply passage (190) communicating with the compression chamber (V, V1, V2) is formed such that at least a portion of the one end is located in an orbiting radius range of the oil supply groove (190) per each pivoting of the orbiting scroll (140).

4. The scroll compressor of claim 3, wherein an inner diameter (D23) of the oil supply passage (190) communicating with the compression chamber is smaller than a wrap thickness (T1) of the orbiting wrap (142), and a width (D5) of the oil supply groove (195) is smaller than or equal to the inner diameter (D23) of the oil supply passage (190).

5. The scroll compressor of any one of claims 1 to 4, wherein the oil supply groove (195) has a same cross-sectional area along a formation direction of the orbiting wrap (142).

6. The scroll compressor of any one of claims 1 to 4, wherein the oil supply groove (195) has different cross-sectional areas along a formation direction of the orbiting wrap (142).

7. The scroll compressor of claim 6, wherein the oil supply groove (195) comprises: a first oil supply groove (1951) communicating with the oil supply passage (190); and a second oil supply groove (1952) communicating with the first oil supply groove (1951) and formed at an outer side in the formation direction of the orbiting wrap (142), compared to the first oil supply groove (1951), and a cross-sectional area of the second oil supply groove (1952) is larger than a cross-sectional area of the first oil supply groove.

8. The scroll compressor of claim 6, wherein the oil supply groove (195) comprises: a first oil supply groove (1951) communicating with the oil supply passage (190); and a second oil supply groove (1952) communicating with the first oil supply groove (1951) and formed at an outer side in the formation direction of the orbiting wrap (142), compared to the first oil supply groove (1951), and a cross-sectional area of the second oil supply groove (1952) is smaller than a cross-sectional area of the first oil supply groove (1951).

9. The scroll compressor of any of claims 1 to 8, wherein the orbiting scroll (140) is made of a material having a greater coefficient of thermal expansion than that of the fixed scroll (150).

10. The scroll compressor of any one of claims 1 to 10, wherein at least a portion of another end of the first oil supply passage (191) and at least a portion of the one end of the second oil supply passage (192) continuously communicate with each other during an orbiting motion of the orbiting scroll (140).

11. The scroll compressor of any one of claims 1 to 10, wherein another end of the first oil supply passage (191) passes through a first thrust surface (140a) of the orbiting scroll (140) opposing the fixed scroll (150), and the one end of the second oil supply passage (192) passes through a second thrust surface (150a) of the fixed scroll (150) opposing the orbiting scroll (140).

12. The scroll compressor of any one of claims 1 to 10, wherein the first oil supply passage (191) comprises: a first orbiting oil supply part (1911) having one end communicating with the oil passage (126) and another end extending toward an outer circumferential surface of the orbiting scroll (140); a second orbiting oil supply part (1912) having one end communicating with the first orbiting oil supply part (1911) and another end open toward the fixed scroll (150); and a third orbiting oil supply part (1913) extending in a circumferential direction from the another end of the second orbiting oil supply part (1912) facing the fixed scroll (150) to communicate with the second oil supply passage (1912).

13. The scroll compressor of any one of claims 1 to 10, wherein the second oil supply passage (192) comprises: a first fixed oil supply part (1921) having one end open on a surface facing the orbiting scroll (140) to communicate with the first oil supply passage (191), and another end extending toward another surface of the fixed scroll (150); a second fixed oil supply part (1922) having one end communicating with the another end of the first fixed oil supply part (1921) and another end extending toward the compression chamber (V, V1, V2); a third fixed oil supply part (1923) having one end communicating with the second fixed oil supply part (1922) and another end open to communicate with the compression chamber (V, V1, V2); and a fourth fixed oil supply part (1924) extending in the circumferential direction from the one end of the first fixed oil supply part (1921) facing the orbiting scroll (140) to communicate with the first oil supply passage (191).