Mutual rotating scroll compressor

Abstract

A mutual rotating scroll compressor includes: a first frame fixed to a casing; a second frame provided with an interval between the first frame and the second frame, a compression space being provided between the first frame and the second frame; a first scroll rotatably supported by the first frame and coupled to a driving motor to rotate in the compression space; a second scroll engaged with the first scroll to rotate about the second frame, the second scroll and the first scroll forming a compression chamber in the compression space; and a bearing housing including a housing part, including a boss accommodation part to which the second scroll is rotatably coupled, and a hinge lug which extends from the housing part and is movably coupled to the second frame.

Claims

1. A mutual rotating scroll compressor comprising: a casing; a driving motor located within the casing; a first frame supported by the casing; a second frame attached to the first frame, the first frame and the second frame together forming a compression space between the first frame and the second frame; a first scroll coupled to the driving motor, the first scroll being rotatably supported by the first frame to rotate within the compression space; a second scroll engaged with the first scroll to rotate with the first scroll within the compression space, the first scroll and the second scroll forming a compression chamber within the compression space; and a bearing housing supporting the second scroll, the bearing housing including: a housing part, the housing part including a boss accommodation part to which the second scroll is rotatably coupled; and a hinge lug extending from the housing part, the hinge lug being movably coupled to the second frame, wherein an axial center of the first scroll defines a first center, wherein an axial center of the boss accommodation part defines a second center, wherein an axial center of the hinge lug defines a third center, wherein the third center of the hinge lug is eccentric with respect to the second center of the boss accommodation part, and wherein the second center of the boss accommodation part and the third center of the hinge lug are each eccentric with respect to the first center of the first scroll.

2. The mutual rotating scroll compressor of claim 1, wherein a line connecting the first center of the first scroll to the second center of the boss accommodation part defines a first virtual line, wherein a line perpendicularly intersecting the first virtual line and passing through the first center of the first scroll defines a second virtual line, wherein the third center of the hinge lug is provided at a position which is spaced apart from each of the first virtual line and the second virtual line by a certain distance, and wherein the second center of the boss accommodation part and the third center of the hinge lug are provided at positions on opposite sides of the second virtual line.

3. The mutual rotating scroll compressor of claim 2, wherein a distance between the third center of the hinge lug and the first center of the first scroll defines a first distance, wherein a distance between the third center of the hinge lug and the second center of the boss accommodation part defines a second distance, and wherein the first distance is shorter than the second distance.

4. The mutual rotating scroll compressor of claim 3, wherein an axial center of the housing part is coincident with the first center of the first scroll.

5. The mutual rotating scroll compressor of claim 1, further comprising a back pressure plate coupled to the first scroll, the back pressure plate being rotatable together with the first scroll, the back pressure plate supporting a rear surface of the second scroll, the back pressure plate having a first end coupled to the first scroll as one body, and the back pressure plate further having a second end rotatably coupled to the bearing housing, wherein a first end of the first scroll in an axial direction is supported in a radius direction by the first frame, and wherein a second end of the first scroll in the axial direction is supported in the radius direction by the bearing housing via the back pressure plate.

6. The mutual rotating scroll compressor of claim 5, wherein the second end the back pressure plate comprises a bearing lug, and wherein the bearing lug is inserted onto and rotatably coupled to an outer circumferential surface of the housing part of the bearing housing.

7. The mutual rotating scroll compressor of claim 5, wherein the back pressure plate further comprises: a plurality of frame parts coupled to the first scroll; and a plate part coupled to the plurality of frame parts, the plate part being located at the rear surface of the second scroll, and wherein the mutual rotating scroll compressor further comprises an anti-rotating member provided between the plate part and the second scroll for preventing rotation of the second scroll with respect to the plate part.

8. The mutual rotating scroll compressor of claim 7, wherein a back pressure chamber is provided between the second scroll and the back pressure plate, the back pressure chamber supporting the second scroll in a direction toward the first scroll, and wherein the anti-rotating member is located in the back pressure chamber.

9. The mutual rotating scroll compressor of claim 8, further comprising: a first sealing member located at a first surface of the plate part that is adjacent to the rear surface of the second scroll; and a second sealing member located at the first surface of the plate part, the second sealing member being spaced radially outwardly of the first sealing member, wherein the back pressure chamber is provided between the first sealing member and the second sealing member, and wherein the anti-rotating member is located in the back pressure chamber between the first sealing member and the second sealing member.

10. The mutual rotating scroll compressor of claim 1, further comprising: a boss part configured to receive a rotational force of the driving motor; an oil discharging path provided in the boss part, the oil discharging path being configured to communicate with the compression chamber to guide compressed refrigerant to an internal space of the casing; and an oil discharging hole provided at an intermediate portion of the oil discharging path, the oil discharging hole passing through the boss part from an inner circumferential surface of the boss part that defines the oil discharging path to an outer circumferential surface of the boss part, wherein an outer end of the oil discharging hole is located between the first frame and the driving motor.

11. The mutual rotating scroll compressor of claim 10, further comprising a stepped surface provided at the intermediate portion of the oil discharging path, the stepped surface being configured to separate oil from the refrigerant.

12. The mutual rotating scroll compressor of claim 11, wherein the boss part comprises: a first boss part provided on the first scroll, the first boss part being supported by the first frame; a rotational shaft having a first end coupled to a rotor of the driving motor and a second end coupled to the first boss part; a discharging port provided in the first boss part, the discharging port sequentially passing from the compression chamber to an end of the first boss part; and a discharging hole passing through the rotational shaft between the first and second ends of the rotational shaft, the discharging hole communicating with the discharging port, and wherein the oil discharging hole and the stepped surface are provided in either the first boss part or the rotational shaft.

13. The mutual rotating scroll compressor of claim 1, wherein the first frame is sealingly coupled to an inner circumferential surface of the casing to form a first internal space between the casing and an upper side of the first frame, wherein the second frame is sealingly coupled to the inner circumferential surface of the casing to form a second internal space between the casing and a lower side of the second frame, wherein the first internal space communicates with the second internal space, wherein the compression space is separated from the first internal space and the second internal space, and further comprising: a suction pipe passing through the casing and into the compression space, a discharging pipe passing through the casing and into the first internal space, and an oil feed path provided in each of the first frame and the second frame, the oil feed path being configured to guide oil from the second internal space to sliding parts of the first frame and the second frame.

14. The mutual rotating scroll compressor of claim 13, further comprising: a first sealing member provided at the first frame to separate the compression space from the first internal space; and a second sealing member provided at the second frame to separate the compression space from the second internal space.

15. A mutual rotating scroll compressor comprising: a casing; a first frame supported by the casing; a bearing part provided in the first frame; a second frame supported by the casing and spaced from the first frame; a hinge groove provided in the second frame, the hinge groove being located eccentrically with respect to the bearing part; a first scroll rotatably supported by the first frame, the first scroll including a first boss part rotatably inserted into the bearing part of the first frame; a second scroll engaged with the first scroll to rotate with the first scroll, the second scroll including a second boss part which is located eccentrically with respect to the first boss part of the first scroll; a bearing housing supporting the second scroll, the bearing housing including: a boss accommodation part into which the second boss part of the second scroll is rotatably inserted; and a hinge lug movably coupled to the hinge groove of the second frame; a back pressure plate, the back pressure plate having a first end coupled to the first scroll, the back pressure plate further having a second end including a bearing lug rotatably inserted onto an outer circumferential surface to the bearing housing; a first bearing provided between the bearing part of the first frame and the first boss part of the first scroll; a second bearing provided between an inner circumferential surface of the back pressure plate and an outer circumferential surface of the bearing housing; and a third bearing provided between the second boss part of the second scroll and an inner circumferential surface of the boss accommodation part of the bearing housing.

16. The mutual rotating scroll compressor of claim 15, wherein an axial center of the third bearing is located at an eccentric distance from an axial center of the first bearing, and wherein the eccentric distance varies as the bearing housing rotates about the hinge lug.

17. The mutual rotating scroll compressor of claim 16, wherein the first scroll includes a first wrap and the second scroll includes a second wrap, the compression chamber being formed between the first wrap and the second wrap, and wherein the axial center of the first bearing and an axial center of the second bearing are coincident when the first wrap contacts the second wrap.

18. A mutual rotating scroll compressor comprising: a driving scroll; a driven scroll driven by the driving scroll to rotate together with the driving scroll; a first member to which the driven scroll is rotatably coupled, the first member being eccentric with respect to a rotational center of the driven scroll, wherein the first member is configured so that a turning radius of the driven scroll with respect to the driving scroll varies; and a second member coupled to the driving scroll, the second member providing a back pressure chamber at a rear surface of the driven scroll, the second member being rotatably inserted onto an outer circumferential surface of the first member.

19. The mutual rotating scroll compressor of claim 18, wherein the first member comprises a hinge lug, the hinge lug being eccentric with respect to a rotational shaft of the driving scroll.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments and together with the description serve to explain the principles of the disclosure.

(2) In the drawings:

(3) FIG. 1 a vertical cross-sectional view illustrating an embodiment of a related art mutual rotating scroll compressor;

(4) FIG. 2 is a cross-sectional view taken along line IV-IV of a bearing part in FIG. 1;

(5) FIG. 3 is a vertical cross-sectional view illustrating an embodiment of a mutual rotating scroll compressor according to the present invention;

(6) FIG. 4 an enlarged vertical cross-sectional view of a compression unit in FIG. 3;

(7) FIGS. 5 and 6 are perspective views illustrating disassembly and assembly of the compression unit in FIG. 3;

(8) FIG. 7 is a plan view of a back pressure plate as seen from a top in FIG. 5;

(9) FIG. 8 is an enlarged perspective view of a bearing housing in FIG. 5;

(10) FIG. 9 is a cross-sectional view taken along line V-V illustrating the inside of the bearing housing in FIG. 8;

(11) FIGS. 10A to 11B are schematic diagrams illustrating, as a vector, a relationship of a force acting on each of bearings and a hinge lug in the mutual rotating scroll compressor of FIG. 3;

(12) FIGS. 12A and 12B are schematic diagrams for describing a sealing force difference based on a shape of a bearing housing in the mutual rotating scroll compressor of FIG. 3;

(13) FIG. 13 is an enlarged view for describing an oil separation structure in the mutual rotating scroll compressor of FIG. 3; and

(14) FIG. 14 is a schematic view for describing a fueling process in the mutual rotating scroll compressor of FIG. 3.

DETAILED DESCRIPTION OF THE DISCLOSURE

(15) Description will now be given in detail of the exemplary embodiments, with reference to the accompanying drawings. For the sake of brief description with reference to the drawings, the same or equivalent components will be provided with the same reference numbers, and description thereof will not be repeated.

(16) Hereinafter, a mutual rotating scroll compressor according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(17) FIG. 3 is a vertical cross-sectional view illustrating an embodiment of a mutual rotating scroll compressor according to the present invention, FIG. 4 an enlarged vertical cross-sectional view of a compression unit in FIG. 3, FIGS. 5 and 6 are perspective views illustrating disassembly and assembly of the compression unit in FIG. 3, and FIG. 7 is a plan view of a back pressure plate as seen from a top in FIG. 5.

(18) As illustrated in FIG. 3, in the mutual rotating scroll compressor (hereinafter referred to as a rotating scroll compressor) according to the present embodiment, a motor unit 20 which configures a driving motor and generates a rotational force may be installed in an internal space of a casing 10 forming a discharging space 10a, and a compression unit 30 which receives the rotational force from the motor unit 20 to compress refrigerants may be installed under the motor unit 20. Depending on the case, the compression unit 30 may be installed on the motor unit 20.

(19) The casing 10 may include a cylindrical shell 11, and an upper shell 12 and a lower shell 13 which cover an upper end and a lower end of the cylindrical shell 11 to configure a sealing vessel. The lower shell 13 may configure the sealing vessel and may form an oil storage space 10b.

(20) A refrigerant suction pipe 15 may pass through a side surface of the cylindrical shell 11, and thus, the cylindrical shell 11 may directly communicate with a suction chamber 30a of the compression unit 30. A refrigerant discharging pipe 16 communicating with the discharging space 10a of the casing 10 may be installed on the upper shell 12. The refrigerant suction pipe 15 may correspond to a path which guides refrigerants from an evaporator of a freezing cycle to a compression space (in detail, the suction chamber 30a of the compression unit) 30 of the casing 10, and the refrigerant discharging pipe 16 may correspond to a path through which compressed refrigerants discharged from the compression unit 30 to the discharging space 10a of the casing 10 are discharged to the outside.

(21) A stator 21 configuring the motor unit 20 may be fixedly installed in an upper portion of the cylindrical shell 11, and a rotor 22 which configures the motor unit 20 along with the stator 21 and rotates through interaction with the stator 21 may be rotatably installed in the stator 21.

(22) In the stator 21, a plurality of slots (not referred to by reference numeral) may be provided on an inner circumference surface of the stator 21 along a circumference direction, a coil 25 may be wound around the stator 21, and an oil collection path 211 which is formed through cutting in a D-cut shape may be formed on an outer circumference surface of the stator 21 so that oil passes through a space between the stator 21 and an inner circumference surface of the cylindrical shell 11.

(23) A main frame (hereinafter referred to as a first frame) 31 may be provided under the stator 21 with a certain interval from a lower end of the stator 21. The first frame 31 may configure the compression unit 30 and may be shrinkage fitted or welded to and fixedly coupled to the inner circumference surface of the cylindrical shell 11.

(24) As illustrated in FIGS. 3 and 4, the first frame 31 may include a circular plate part 311 and a ring-shaped wall part 312.

(25) A bearing part 313, into which a first boss part 333 of a rotational shaft 23 to be described below is inserted into and rotatably coupled to, may be provided in a center portion of the circular plate part 311. A first driving bearing 313a configuring a first bearing may be installed on an inner circumference surface of the bearing part 313. The first driving bearing 313a may include a bush bearing or a ball bearing such as angular.

(26) The ring-shaped wall part 312 may be provided in a cylindrical shape as in FIG. 4. However, the ring-shaped wall part 312 may be provided in plurality, and the plurality of ring-shaped wall parts 312 may be arranged at certain intervals along a circumference direction.

(27) A sub-frame (hereinafter referred to as a second frame) 32 may be installed under the first frame 31 in an axial direction and may be spaced apart from the first frame 31 by a certain interval.

(28) As illustrated in FIGS. 3 and 4, the second frame 32 may be shrinkage fitted or welded to and fixed to the inner circumference surface of the cylindrical shell 11 as in the first frame 31. However, the second frame 32 may be fastened and fixed to the ring-shaped wall part 312 of the first frame 312 by a bolt. On the other hand, the second frame 32 may be fixed to the cylindrical shell 11, and the ring-shaped wall part 312 of the first frame 31 may be fastened to the second frame 31 by a bolt. Therefore, the first frame 31 may be spaced apart from the second frame 32 by a height of the ring-shaped wall part 312, and thus, the first and second frames 31 and 32 may form the compression space 30a including a suction chamber.

(29) A hinge groove, which a hinge lug 375 of a bearing housing 37 to be described below is inserted into and rotatably coupled to, may be provided in a center portion of the second frame 32. A hinge groove 321 may be formed as a hinge hole depending on the case, but for convenience, the hinge groove 321 may be referred to as a hinge groove.

(30) As in FIG. 4, a center (hereinafter referred to as a center of a driven bearing, a center of the hinge lug, or a third center) O3 of the hinge groove 321 may be provided on the same axis as a center (hereinafter referred to as a center of a first driving bearing, a center of a second bearing, or a first center) O1 of the bearing part 313. However, in order to increase a sealing force between wraps against a gas repulsion, the center O3 of the hinge groove may be eccentric from the center of the bearing part on a plane. This will be described below.

(31) A driving scroll 33, which is coupled to the rotational shaft 23 to rotate, may be rotatably coupled to the first frame 31. A driven scroll 34, which is engaged with the driving scroll 33 and is rotated by the driving scroll 33, may be rotatably coupled to the second frame 32.

(32) Therefore, the driving scroll 33 and the driven scroll 34 which forms a pair of compression chambers V between the driving scroll 33 and the driven scroll 34 may be provided between the first frame 31 and the second frame 32. Hereinafter, for convenience, the driving scroll may be referred to as a first scroll, and the driven scroll may be referred to as a second scroll. Also, first may be given to a portion relevant to the first scroll, and second may be given to a portion relevant to the second scroll.

(33) As in FIGS. 4 to 6, in the first scroll 33, a first end plate 331 may be provided in an approximately circular plate shape, a first wrap 332 which is engaged with a below-described second wrap 342 to configure a compression chamber V may be provided on a bottom of the first end plate 331, and a first boss part 333 which is rotatably supported by the bearing part 313 of the first frame 31 may be provided in a center of a top of the first end plate 331 to extend in an axial direction. A below-described discharging port 335 may be provided to pass through the first boss part 333, and the discharging port 335 may communicate with a discharging hole 231 which is provided to pass through the inside of the rotational shaft 23.

(34) The first wrap 332 may be provided in an involute shape where a wrap thickness is equal, provided in an algebraic shape where a wrap thickness in a discharging side varies formally, or provided in a shape where a wrap thickness is non-formal.

(35) Moreover, a suction port 334 may be provided in an edge of the first end plate 331, and a discharging port 335 through which compressed refrigerants are discharged may be provided in a center of the first end plate 331. The suction port 334 may be spaced apart from an outer surface of the first wrap 332 adjacent to an outer end of the first wrap 332 in a radius direction and may naturally configure a suction portion. The discharging port 335 may be provided to pass through the first end plate 331 in an axial direction. The discharging port 335 may be variously provided based on a discharging manner, but as described above, the discharging port 335 may be provided to pass through the first boss part 333 and communicate with the discharging hole 231 of the rotational shaft 23 commonly.

(36) A back pressure plate 35 supporting the second scroll 34 may be coupled to an edge bottom of the first end plate 331. Therefore, a space may be formed between the first scroll 33 and the back pressure plate 35, and the second scroll 34 may be rotatably provided in the space.

(37) As in FIGS. 4 and 5, the back pressure plate 35 may include a frame part 351, which is fixed to the first end plate 331 and extends in an axial direction, and a plate part 355 which is included in the frame part 351 and supports a bottom of the second scroll 34.

(38) The frame part 351 may be provided in plurality along a circumference direction, and the plurality of frame parts 351 may be arranged at certain intervals along the circumference direction, and a space between adjacent frame parts 351 may form a suction path 351a.

(39) Moreover, upper ends of the frame parts 351 may be connected to one another by one ring-shaped ring 352, and the ring-shaped ring 352 may be fastened to a bottom of the first end plate 331 by a bolt. Therefore, the first scroll 33 may be coupled to the back pressure plate 35 as one body and may rotate together.

(40) As in FIGS. 4 and 5, the plate part 355 may be provided in a circular plate shape, and a below-described bearing housing 37 may be inserted into a center portion of the plate part 355, whereby a bearing lug 356 supported by the bearing housing 37 in the radius direction may be provided. The bearing lug 356 may be provided to protrude by a certain height in a direction from a bottom of the plate part 355 to the second frame 32. However, if a thickness of the plate part 355 is thick, the bearing lug 356 may be provided in a groove or hole form like the bearing part 313.

(41) A second driving bearing 356a which supports a portion between the bearing lug 356 and an outer circumference surface of the below-described bearing housing 37 and configures the second bearing may be installed on an inner circumference surface of the bearing lug 356. The second driving bearing 356a may include a bush bearing or a ball bearing such as angular like the first driving bearing 313a.

(42) Moreover, as in FIGS. 4 and 7, a thrust surface 357 may be provided on a top of the plate part 355 in order for a bottom of a below-described second end plate 341 to be supported in an axial direction. The thrust surface 357 may be provided in a ring shape having a certain height, and an inner thrust surface 357a and an outer thrust surface 357b may be provided along the radius direction with an interval therebetween.

(43) Moreover, a sealing groove 357c may be formed in the inner thrust surface 357a to have a certain depth, and another sealing groove 357c may be formed in the outer thrust surface 357b to have a certain depth. A back pressure chamber sealing member (hereinafter referred to as a sealing member) 358a (358b) closely adhered to a bottom (a rear surface) of the second end plate 341 may be inserted into each of a plurality of sealing grooves 357c. Therefore, a certain space may be formed between the inner thrust surface 357a and the outer thrust surface 357b, and in detail, between two sealing members 358. The space may communicate with an intermediate pressure chamber Vm of the compression chamber V, and thus, a back pressure chamber S may be provided.

(44) Here, the inner circumference surface of the bearing lug 356 may be inserted to face an outer circumference surface of a housing part 371 of the below-described bearing housing 37, and thus, a gap G between the bearing lug 356 and a below-described second boss part 343 may be reduced. Therefore, an internal diameter D2 of the bearing lug 356 may be reduced, and thus, a diameter D3 of the sealing member 358 may be reduced, thereby decreasing frictional loss between a top of the sealing member 358 and a bottom of the second scroll 34.

(45) Moreover, a pin ring unit 36 may be installed in the back pressure chamber S along the circumference direction. The pin ring unit 36 may include a plurality of rings 361, which are mounted on a top of the plate part 355, and a plurality of pins 362 which are mounted on a bottom of the second end plate 341 corresponding to the plate part 355 and are respectively inserted into the rings 361.

(46) To this end, a plurality of ring grooves 355a may be provided at certain intervals along the circumference direction on a top of the plate part 355 so that the rings 361 are respectively inserted into the ring grooves 355a. The pin may be coupled to the plate part, but in this case, since the ring should be inserted into a bottom of the second end plate, there can be difficulty in terms of an assembly process. In this manner, if the pin ring unit 36 which is an anti-rotating mechanism is installed in the back pressure chamber S, a space for installing the anti-rotating mechanism is not separately provided, and thus, the compressor can be miniaturized. Also, the anti-rotating mechanism may be installed on a rear surface of the second scroll 34, and thus, the suction path 351 is not plugged, thereby preventing suction loss.

(47) As in FIGS. 4 to 6, in the second scroll 34, the second end plate 341 may be provided in a circular plate shape, a second wrap 342 which is engaged with the first wrap 332 to configure the compression chamber V may be provided on a top of the second end plate 341, and a second boss part 343 which is coupled to the bearing housing 37 and is rotatably coupled to the second frame 32 may be provided in a center of a bottom of the second end plate 341.

(48) The second end plate 341 may be supported by the plate part 355 of the back pressure plate 35 to rotate, and an external diameter of the second end plate 341 may be set less than an internal diameter of the frame part 351 of the back pressure plate 35. Therefore, the second scroll 34 may perform a rotational movement independently from the first scroll 33 and may perform a relative turning movement with respect to the first scroll 33.

(49) Moreover, a back pressure hole 341a may be provided in a center portion of the second end plate 341 in an axial direction or an inclined direction to pass through the center portion of the second end plate 341, so that some of refrigerants compressed in the compression chamber V are transferred to the back pressure chamber S. Therefore, refrigerants having an intermediate pressure in an intermediate pressure chamber Vm may flow into the back pressure chamber S, and thus, a pressure of the back pressure chamber S may be maintained as an intermediate pressure.

(50) The second wrap 342 may be provided in an involute shape, an algebraic shape, or a non-formal shape like the first wrap 332. Accordingly, the second wrap 342 may be engaged with the first wrap 332 to configure a pair of compression chambers V1 and V2.

(51) The compression chamber V may be provided between the first end plate 331, the first wrap 332, the second wrap 342, and the second end plate 341, and a as suction chamber Vs, the intermediate pressure chamber Vm, and a discharging chamber Vd may be continuously provided along a direction in which a wrap travels.

(52) Here, the compression chamber V may include a first compression chamber V1, which is provided between an inner surface of the first wrap 332 and an outer surface of the second wrap 342, and a second compression chamber V2 which is provided between an outer surface of the first wrap 332 and an inner surface of the second wrap 342.

(53) Moreover, the second boss part 343 may be provided to protrude by a certain height from a bottom of the second end plate 341, and a center (hereinafter referred to as a center of a driven bearing or a second center) O2 of the second boss part 343 may be provided to be offset by an eccentric distance 1 with respect to a center (hereinafter referred to as a first center) O1 of the first boss part 333. Therefore, when the first scroll 33 is rotating, the second wrap 342 may contact the first wrap 332, and thus, the second scroll 34 may be provided with a rotational force of the first scroll 33 and may be rotated by the first scroll 33 to form the compression chamber V between the first wrap 332 and the second wrap 342.

(54) Moreover, a bottom of the second boss part 343 may be supported by the below-described bearing housing 37 in an axial direction, and the bearing housing 37 may be supported by the second frame 32 in an axial direction. Therefore, the second scroll 34 may be supported by the bearing housing 37 in an axial direction, and the first scroll 33 may be supported by the second scroll 34 in an axial direction. However, the second scroll 34 may be supported by the bearing housing 37 and the back pressure plate 35 in an axial direction, and the first scroll 33 may be supported by the second scroll 34 in an axial direction.

(55) The hinge groove 321 may be formed in a center top of the second frame 32, and the hinge lug 375 of the bearing housing 37 may be inserted into and rotatably coupled to the hinge groove 321. A center O3 of the hinge groove 321 may be provided to form concentricity with a center (which is the same as a center of the bearing part) O1 of the first driving bearing 313a and may be provided so as to be eccentric.

(56) Here, in a state where the second scroll 34 coupled to the bearing housing 37 is not engaged with the first scroll 33, the hinge lug 375 may freely rotate in the hinge groove, between an inner circumference surface of the hinge groove 321 and an outer circumference surface of the hinge lug 375. However, in a state where the second scroll 34 is engaged with the first scroll 33, a rotational center of the first scroll 33 and a rotational center of the second scroll 34 may be located on different axial lines, and thus, the hinge lug 375 cannot freely rotate in the hinge groove 321.

(57) FIG. 8 is an enlarged perspective view of a bearing housing in FIG. 5, and FIG. 9 is a cross-sectional view taken along line V-V illustrating the inside of the bearing housing in FIG. 8.

(58) As illustrated in the drawings, the bearing housing 37 may include the housing part 371, to which the second scroll 34 is coupled, and the hinge lug 375 coupled to the second frame 35.

(59) A boss accommodation groove 372 into which the second boss part 343 is inserted may be provided on a top of the housing part 371 and may be recessed by a certain depth, and a driven bearing 372a which supports an outer circumference surface of the second boss part 343 in the radius direction and configures a third bearing may be provided on an inner circumference surface of the boss accommodation groove 372. The driven bearing 372a may be coupled to the outer circumference surface of the second boss part 343.

(60) The boss accommodation groove 372 may be provided so that a center (a second center) O2 thereof is eccentric with respect to a center (a first center) O1 of the housing part 371 on a plane. Therefore, a center O2 of the driven bearing 372a may be located at a position which is spaced apart from the center (the first center) O1 of the first driving bearing 313a by the eccentric distance 1.

(61) Moreover, the bearing lug 356 of the back pressure plate 35 may be rotatably inserted onto an outer circumference surface of the housing part 371, and the second driving bearing 356a may be provided between the outer circumference surface of the housing part 371 and the inner circumference surface of the bearing lug 356, whereby the back pressure plate (i.e., the first scroll) 35 may be supported by the bearing housing 37 in the radius direction.

(62) The hinge lug 375 may extend and protrude from a bottom of the housing part 371 by a certain height.

(63) As in FIG. 9, an external diameter D5 of the hinge lug 375 may be provided less than an external diameter D4 of the housing part 371. Therefore, the bottom of the housing part 371 may configure a housing-side thrust surface 371a in contact with a frame-side thrust surface 32a near the hinge groove 321 of the second frame 32 and may configure a thrust bearing surface along with the frame-side thrust surface 32a.

(64) However, for convenience, as illustrated in FIG. 9, the hinge groove 321 of the second frame 32 may have a plugged structure, and thus, a bottom 375b of the hinge lug 375 may configure a thrust bearing surface on a bottom 321a of the hinge groove 321. In this case, the bottom of the housing part 371 may be spaced apart from a top of the second frame 32 by a certain interval, thereby preventing frictional loss from occurring. Accordingly, in this case, an area of the thrust bearing surface is relatively reduced, and thus, frictional loss is reduced in proportion to the reduced area.

(65) Here, in order to prevent an excessive adhesiveness between wraps, the hinge lug 375 may be provided at a position, at which the center O1 of the housing part matches the center O1 of the first driving bearing, at a time when the first wrap 332 contacts the second wrap 342.

(66) Moreover, as in FIG. 9, the hinge lug 375 may be provided so that a center (a third center) O3 thereof is eccentric with respect to the center O1 of the housing part 371 on a plane. Therefore, the third center O3 which is a center of the hinge lug 375 in an axial direction may be eccentric with respect to the second center O2, which is a center of the boss accommodation groove 372 in an axial direction, on a plane. Each of the second center O2 and the third center O3 may be eccentric with respect to the first center O1, which is a center of the first scroll 33 in an axial direction, on a plane.

(67) That is, the hinge lug 375 may be provided at a position which is eccentric with respect to the housing part 371 and is eccentric with respect to the boss accommodation groove 372, and the boss accommodation groove 372 may be eccentric with respect to the housing part 371 in a direction in which the housing part 371 is eccentric.

(68) FIGS. 10A to 11B are schematic diagrams illustrating, as a vector, a relationship of a force acting on each of bearings and a hinge lug in the mutual rotating scroll compressor of FIG. 3.

(69) As in FIG. 10A, when it is assumed that a virtual line which connects the center O1 of the housing part and the center O2 of the second boss is referred to as a first center line CL1, and a virtual line which perpendicularly intersects the first center line CL1 and passes through the center O1 of the housing part is referred to as a second center line CL2, the third center O3 may be provided at a position which is spaced apart from each of the first virtual line CL1 and the second virtual line CL2 by a certain distance on the opposite side of the second center O2 with respect to the second virtual line CL2.

(70) Therefore, as in FIG. 10B, a gas force Fr in a r direction which is a direction in which the second wrap 342 deviates from the first wrap 332 and a t direction gas force Ft which resists a torque of the second scroll may act on the second center O2 which is a center of the boss accommodation groove 372 coupled to the second scroll 34, and a force (i.e., a sealing force Fseal) for offsetting a moment may act in the r direction. Also, a r direction gas force Fr, a t direction gas force Ft, and a r direction sealing force Fseal which are repulsions against the gas force and the sealing force may act on the first center O1 which is the center of the second driving bearing. With respect to the third center O3 which is a rotational center of the hinge lug, a distance a to the first center O1 may differ from a distance b to the second center O2, and the first center O1 and the second center O2 may be spaced apart from the first virtual line CL1, which connects the first center O1 to the second center O2, by a distance d. Therefore, a moment may be generated in the third center O3 which is the rotational center of the hinge lug 375, and a force which resists the moment may be converted into a sealing force, whereby the first wrap 332 and the second wrap 342 may be closed adhered to each other to seal the compression chamber.

(71) Here, as in FIGS. 11A and 11B, the r direction gas force, the sealing force, and the t direction gas force which are transferred from the first scroll 33 and the second scroll 34 may act on the housing part 371 of the bearing housing 37, and simultaneously, the r direction gas force, the sealing force, and the t direction gas force which are repulsions against the r direction gas force and the sealing force may act on the housing part 371 of the bearing housing 37. Therefore, an r direction repulsion Rr and a t direction repulsion Rt may act between the second frame 32 and the hinge groove 321 as repulsions against the gas force and the sealing force. Accordingly, the first scroll 33 and the second scroll 34 may be supported by the bearing housing 37 in the radius direction, and thus, may stably and continuously perform a mutual rotational movement without being keeled.

(72) In the drawings, reference numeral 232 refers to an oil discharging hole, reference numeral 375a refers to an oil flow hole, and F refers to an oil collection path.

(73) The rotating scroll compressor according to the present embodiment may operate as follows.

(74) That is, when power is applied to the motor unit 20, a rotation force may be generated in the rotor 22, and thus, the rotor 22 may rotate. When the rotor 22 rotates, the rotational shaft 23 coupled to the rotor 22 may rotate.

(75) Then, the first boss part 333 coupled to the rotational shaft 23 may receive the rotational force to rotate the first scroll 33. At this time, an upper end of the first boss part 333 of the first scroll 33 may be supported by the first driving bearing 313a included in the bearing part 313, and simultaneously, a lower end of the bearing lug 356 of the back pressure plate 35 coupled to the first scroll 33 may be supported by the second driving bearing 356a provided between the bearing lug 356 and the bearing housing 37. Therefore, each of an upper end and a lower end of the first scroll 33 may be supported in the radius direction with respect to the first wrap 332, thereby preventing the first scroll 33 from being keeled. Accordingly, in the present embodiment, a degree to which the first scroll 33 is inclined with respect to an axial center is minimized, and thus, a gap is prevented from occurring between the first wrap 332 and the second end plate 341 or between the first end plate 331 and the second wrap 342, thereby effectively preventing leakage in an axial direction from the compression chamber.

(76) Therefore, the first scroll 332 may rotate to transfer a rotational force to the second wrap 342 of the second scroll 34 engaged with the first scroll 33, and thus, the second scroll 34 may rotate about the second boss part 343. Therefore, the pair of compression chambers V1 and V2 may be provided between the first wrap 332 and the second wrap 342. At this time, in the second scroll 34, the second boss part 343 may be disposed so as to be eccentric with respect to the first boss part 333 by the bearing housing 37, and simultaneously, the hinge lug 375 which is the center of the hearing housing 37 may be disposed so as to be eccentric with respect to the first boss part 333 and the second boss part 343. Therefore, the eccentric distance 1 between the first driving bearing 313a and the driven bearing 372a may vary due to a gas repulsion, and thus, when the compressor is driving, a gas repulsion occurring the second scroll 34 may be converted into the sealing force Fseal, thereby preventing leakage in the radius direction.

(77) Here, as in FIG. 12A, in a case where the center O3 of the hinge groove 321 is provided to form concentricity with the rotational center (hereinafter referred to as a center of the outer circumference surface of the housing part, a center of the housing part, or a center or a first center of the second driving bearing) O1 of the first driving bearing 313a, even though the center O1 of the housing part is provided so as to be eccentric with respect to a rotational center (hereinafter referred to as a center or a second center of the second boss part) O2 of a below-described driven bearing, an eccentric distance 1 of the driven bearing with respect to the center O3 of the hinge groove may be constant when the bearing housing 37 rotates (rotates based on a moment). Therefore, a trajectory of the second center maintains the constant eccentric distance 1 of the driven bearing which is the same as a turning radius of the second scroll 34 with respect to the first scroll 33, and in a compression stroke, when the first wrap 332 and the second wrap 342 respectively receive the gas force Fr and the gas force Fr in the r direction deviating from each other, a gap between the first wrap 332 and the second wrap 342 is widened, causing leakage in the radius direction.

(78) However, as in FIG. 12B, in a case where the center O3 of the hinge groove is spaced apart from the rotational center O1 of the first driving bearing by an eccentric distance 2 on a plane and is eccentric with respect to the rotational center O1, the rotational center O3 of the below-described bearing housing 37 may be eccentric with respect to the rotational center O1 of the first driving bearing, and thus, when the bearing housing 37 rotates, the eccentric distance 1 of the driven bearing with respect to the center O3 of the hinge groove may vary. Therefore, in a case where the hinge groove (i.e., a position of the third center O3 with respect to the first center O1 and the second center O2) is disposed at an appropriate position (i.e., a position (i.e., a position at which a sealing force allowing a moment in the third center O3 to become zero is generated) at which a moment for generating a desired sealing force is generated), even when the first wrap 332 and the second wrap 342 respectively receive the gas force Fr and the gas force Fr in the r direction deviating from each other in a compression stroke, a moment may be converted into a sealing force, and thus, as in a dotted line of the drawing, a position of the bearing housing 37 may be compensated for, a state where the first wrap 332 and the second wrap 342 are closely adhered to each other is maintained, and a leakage of refrigerants in the radius direction is prevented.

(79) Therefore, refrigerants compressed in the first compression chamber V1 and the second compression chamber V2 may be guided to the discharging hole 231 of the rotational shaft 23 through the discharging port 335, and the refrigerants guided to the discharging hole 231 may move to an upper end of the rotational shaft 23, may be discharged to a discharging space 10a of the casing 10, and may be discharged to the outside of the compressor through the discharging pipe 16. In this case, the oil discharging hole 232 may be formed in a middle portion of the discharging hole 231, and thus, oil may be separated from the refrigerants moving through the discharging hole 231. The separated oil may be discharged to the discharging space 10a of the casing 10 through the oil discharging hole 232 and may be collected to the oil storage space 10b, which is a lower space of the casing 10, through an oil collection path F included in each of the first frame 31 and the second frame 32. Such a process may be repeated.

(80) Here, an oil separation surface 233 for separating oil from refrigerants moving an upper end of the rotational shaft 23 through the discharging hole 231 may be provided in a middle portion of the discharging hole 231 to have a step height, and in more detail, may be provided on an upper side close to the oil discharging hole 232 as in FIG. 13.

(81) Therefore, refrigerants moving to the upper end through the discharging hole 231 may contact the oil separation surface 233, and thus, heavy oil may be separated from the refrigerants. The separated oil may be discharged to the discharging space through the oil discharging hole 232 by a centrifugal force, but the refrigerants may move to an upper end of the rotational shaft 23 through the discharging hole 231.

(82) In the above-described mutual rotating scroll compressor according to the present invention, a separate oil pump may be applied for supplying oil to a sliding part, but as a high pressure is formed in an internal space of the casing, oil may be fed by using a pressure difference.

(83) For example, as in FIG. 14, an upper separation member 381 may be installed between the bottom of the first frame 31 and the top (the rear surface) of the first scroll 33, and a lower separation member 382 may be installed between the bearing lug 356 of the back pressure plate 35 and the top of the second frame 32. Accordingly, the compression space 30a of the compression unit 30 may be separated from the internal spaces 10a and 10b of the casing 10.

(84) Here, the upper separation member 381 and the lower separation member 382 may each be provided in a ring shape. The upper separation member 381 may be fixedly coupled to a top of the first end plate 331, and the lower separation member 382 may be fixedly coupled to the top of the second frame 32 so as to be sealed to a bottom of the bearing lug 356.

(85) Moreover, an oil flow path may be formed between the upper separation member 381 and the lower separation member 382, and thus, oil filled into the oil storage space 10b of the casing 10 may be provided to the first driving bearing 313a, the second driving bearing 356a, and the driven bearing 372a.

(86) Here, the oil flow path may pass through the hinge lug 375 of the bearing housing 37 and may include a gap between each of the bearings 372a, 356a, and 313a and a member supported by a corresponding bearing and flow paths F2 which respectively pass through the first frame 31 and the second frame 32.

(87) That is, oil stored in the oil storage space 10b may flow into the boss accommodation groove 372 through the oil flow hole 375a passing through the hinge lug 375 of the bearing housing 37, and the oil may lubricate the driven bearing 372a. Some of the oil may lubricate a thrust surface between the second scroll 34 and the back pressure plate 35 and may move toward the compression chamber V, and the other oil may move toward the second driving bearing 356a.

(88) Moreover, oil which has lubricated the second driving bearing 356a may pass through the oil flow paths F2 of the first frame 31 and the second frame 32 through the outer circumference surface of the hinge lug 375 and the inner circumference surface of the hinge groove 321 and may lubricate the first driving bearing 313a. The oil may be provided to the intermediate pressure chamber Vm or the suction chamber Vs through an oil feed hole 331a included in the first scroll 33.

(89) In this case, a pressure of the oil storage space 10b is a high pressure, and the compression space 30a may have an intermediate pressure. Therefore, the oil stored in the oil storage space 10b may move along the oil flow path F according to a pressure difference and may be provided to a sliding part of each of the hinge groove, the inner circumference surface of the first driving bearing, the inner circumference surface of the second driving bearing, and the inner circumference surface of the driven bearing.

(90) Subsequently, oil which is discharged through the discharging port 335 along with refrigerants may be separated from the refrigerants by a centrifugal force and the oil separation surface 233 while passing through the discharging port 335, and the refrigerants may be discharged to the discharging space 10a of the casing 10 through the discharging hole 231. On the other hand, the oil may be previously discharged to an internal space (a lower space of the motor unit) of the casing 10 through the oil discharging hole 232 and may be collected to the oil storage space 10b of the casing 10 through the oil collection path F1. Such a process may be repeated.

(91) The foregoing embodiments and advantages are merely exemplary and are not to be considered as limiting the present disclosure. The present teachings can be readily applied to other types of apparatuses. This description is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. The features, structures, methods, and other characteristics of the exemplary embodiments described herein may be combined in various ways to obtain additional and/or alternative exemplary embodiments.

(92) As the present features may be embodied in several forms without departing from the characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be considered broadly within its scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.