CN117108502A - Scroll compressor and refrigeration cycle device - Google Patents

Abstract

The invention provides a highly reliable scroll compressor and the like. An orbiting scroll of a scroll compressor is provided with an oil supply passage for guiding lubricating oil from an oil supply through hole to a mirror surface side of a fixed scroll (21), a circumferential groove (G1) intermittently communicating with the oil supply passage is provided on the mirror surface side of the fixed scroll (21), an oil drain groove (G2) intermittently communicating with a back pressure chamber is provided on the mirror surface side of the orbiting scroll, the oil drain groove (G2) intermittently communicates with the circumferential groove (G1), and communication between the oil drain groove (G2) and the circumferential groove (G1) is ended while the oil supply passage communicates with the circumferential groove (G1).

Description

Scroll compressor and refrigeration cycle device

Technical Field

The present invention relates to scroll compressors and the like.

Background

As a technique for maintaining a thrust load (axial force) from one of the fixed scroll and the orbiting scroll to the other in an appropriate range, for example, a technique described in patent literature 1 is known. That is, patent document 1 describes the following: an oil groove is formed in the thrust sliding surface of the fixed scroll so as to extend in the circumferential direction, and an end portion of the oil groove communicates with the negative pressure region.

Prior art literature

Patent literature

Japanese patent document 1 laid-open publication 2016-20664

Disclosure of Invention

Problems to be solved by the invention

In the technique described in patent document 1, since the oil groove of the fixed scroll always communicates with the negative pressure region, the pressure of the lubricating oil in the oil groove is likely to be reduced, and the thrust load may not be sufficiently reduced. Accordingly, the technique described in patent document 1 has room for improvement in terms of reliability of the scroll compressor.

Accordingly, an object of the present invention is to provide a highly reliable scroll compressor and the like.

Means for solving the problems

In order to solve the above problems, a scroll compressor according to the present invention includes: a closed container; a motor having a stator and a rotor, and accommodated in the closed container; a shaft having an oil supply through hole through which lubricating oil flows, and rotating integrally with the rotor; a fixed scroll having a scroll-like fixed overlap; an orbiting scroll having an orbiting scroll in a spiral shape, a compression chamber being formed between the fixed scroll and the orbiting scroll; and a frame having the shaft insertion hole, supporting the fixed scroll, wherein a back pressure chamber is provided between the orbiting scroll and the frame, wherein an oil supply passage for guiding the lubricating oil from the oil supply through hole to a mirror surface side of the fixed scroll is provided to the orbiting scroll, wherein a circumferential groove intermittently communicating with the oil supply passage is provided to the mirror surface side of the fixed scroll, wherein the circumferential groove is not communicated with a suction port of the fixed scroll, wherein an oil drain groove intermittently communicating with the back pressure chamber is provided to the mirror surface side of the orbiting scroll, wherein the oil drain groove communicates with the circumferential groove at the start of communication between the oil supply passage and the circumferential groove, and wherein communication between the oil drain groove and the circumferential groove is ended while the oil supply passage communicates with the circumferential groove.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a highly reliable scroll compressor or the like can be provided.

Description of the drawings

Fig. 1 is a longitudinal sectional view of a scroll compressor of a first embodiment.

Fig. 2 is a longitudinal sectional view of an orbiting scroll provided in the scroll compressor of the first embodiment.

Fig. 3 is a perspective view of an orbiting scroll provided in the scroll compressor of the first embodiment.

Fig. 4 is a bottom view of a fixed scroll provided in the scroll compressor of the first embodiment.

Fig. 5 is an explanatory diagram showing a movement path of an opening of the oil supply passage in the scroll compressor according to the first embodiment by partially enlarging a region K1 in fig. 4.

Fig. 6A is an explanatory view of a state in which an opening of an oil supply flow path of an orbiting scroll is not communicated with a circumferential groove and an oil discharge groove is not communicated with the circumferential groove in the scroll compressor of the first embodiment.

Fig. 6B is an explanatory view of a state in which an opening of an oil supply flow path of an orbiting scroll communicates with a circumferential groove and an oil discharge groove also communicates with the circumferential groove in the scroll compressor of the first embodiment.

Fig. 6C is an explanatory view of a state immediately after the end of communication between the oil drain groove and the circumferential groove in the scroll compressor of the first embodiment.

Fig. 6D is an explanatory view of a state immediately after the end of communication between the opening of the oil supply passage of the orbiting scroll and the circumferential groove in the scroll compressor of the first embodiment.

Fig. 7 is a timing chart showing a communication state of the circumferential grooves of the scroll compressor of the first embodiment.

Fig. 8 is a perspective view of an orbiting scroll provided in the scroll compressor of the second embodiment.

Fig. 9 is a bottom view of a fixed scroll provided in the scroll compressor of the second embodiment.

Fig. 10A is an explanatory view of a state in which the opening of the oil supply passage of the orbiting scroll is not communicated with the circumferential groove and the oil drain groove is not communicated with the back pressure chamber in the scroll compressor of the second embodiment.

Fig. 10B is an explanatory view of a state in which an opening of an oil supply flow path of the orbiting scroll communicates with a circumferential groove and an oil drain groove communicates with a back pressure chamber in the scroll compressor of the second embodiment.

Fig. 10C is an explanatory view of a state immediately after the communication between the oil drain groove and the back pressure chamber is completed in the scroll compressor of the second embodiment.

Fig. 10D is an explanatory view of a state immediately after communication between the opening of the oil supply passage of the orbiting scroll and the circumferential groove is completed in the scroll compressor of the second embodiment.

Fig. 11 is a configuration diagram of a refrigerant circuit including an air conditioner according to the third embodiment.

Fig. 12 is an explanatory diagram showing a movement trajectory of an opening of an oil supply flow path of an orbiting scroll in the scroll compressor of the first modification.

Fig. 13 is an explanatory diagram showing a movement trajectory of an opening of an oil supply flow path of an orbiting scroll in a scroll compressor of a second modification.

In the figure: 1-closed vessel, 2-compression mechanism part, 12-oil supply flow path, 21A-fixed scroll, 21 b-fixed overlapping piece, 21f, 21 Af-mirror plate surface (mirror plate surface of fixed scroll), 22-orbiting scroll, 22 b-orbiting overlapping piece, 22d, 22 Ad-mirror plate surface (mirror plate surface of orbiting scroll), 23-frame, 3-crankshaft (shaft), 3 c-oil supply piece (centrifugal pump), 3 d-oil supply through hole, 4-motor, 4 a-stator, 4 b-rotor, 71-outdoor heat exchanger, 73-expansion valve, 75-indoor heat exchanger, 100-scroll compressor, G1, GA1, GB 1-circumferential groove, G11-circular arc part, G12, G13, G14-communication part, G2-oil drain groove (oil drain groove of scroll), GA 2-oil drain groove (oil drain groove of fixed scroll), H1-insertion hole, J4-opening, M4-moving track, S1-compression chamber, S4-chamber, W1-back pressure circulation device (air conditioner).

Detailed Description

First embodiment

< Structure of scroll compressor >

Fig. 1 is a longitudinal sectional view of a scroll compressor 100 according to a first embodiment.

The scroll compressor 100 is a device for compressing a gaseous refrigerant. As shown in fig. 1, the scroll compressor 100 includes a closed casing 1, a compression mechanism 2, a crankshaft 3 (shaft), a motor 4, a main bearing 5, and a swivel bearing 6. In addition to the above configuration, the scroll compressor 100 further includes an cross ring 7, a counterweight 8, a subframe 9, a power supply terminal 10, and a leg 11.

The closed casing 1 is a casing-like casing that houses the compression mechanism 2, the crankshaft 3, the motor 4, and the like, and is substantially closed. The sealed container 1 is filled with lubricating oil for lubricating the compression mechanism 2 and the bearings, and the bottom of the sealed container 1 is stored as an oil storage portion E1. The closed container 1 includes a cylindrical tube chamber 1a, a lid chamber 1b closing the upper side of the tube chamber 1a, and a bottom chamber 1c closing the lower side of the tube chamber 1 a.

A suction pipe P1 is inserted into and fixed to the lid chamber 1b of the closed casing 1. The suction pipe P1 is a pipe for guiding the refrigerant to the suction port J1 of the compression mechanism 2. Further, a discharge pipe P2 is inserted and fixed into the cylinder chamber 1a of the closed casing 1. The discharge pipe P2 is a pipe for guiding the refrigerant compressed by the compression mechanism 2 to the outside of the scroll compressor 100.

The compression mechanism 2 compresses a gaseous refrigerant in accordance with rotation of the crankshaft 3. The compression mechanism 2 includes a fixed scroll 21, an orbiting scroll 22, and a frame 23, and is disposed in an upper space in the sealed container 1.

The fixed scroll 21 is a member that forms a compression chamber S1 together with the orbiting scroll 22. The fixed scroll 21 is provided above the frame 23, and is fixed to the frame 23 by a bolt B1. As shown in fig. 1, the fixed scroll 21 includes a platen 21a and a fixed lap 21b.

The platen 21a is a member having a circular wall thickness in a plan view. The platen 21a is provided with a suction port J1 for guiding the refrigerant through a suction pipe P1. In addition, a region S2 recessed upward in a predetermined manner is provided at a lower portion near the center of the platen 21 a. The fixing overlapping piece 21b is in a spiral shape (see also fig. 4), and extends downward from the table 21a in the above-described region S2. In addition, the lower surface of the platen 21a (the lower surface of the portion outside the region S2) is substantially coplanar with the tooth tip of the fixed overlap 21b.

The lower surface of the platen 21a is referred to as a mirror plate surface 21f of the fixed scroll 21 (see also fig. 4). The mirror plate surface 21f is provided with a circumferential groove G1 (see also fig. 4) to which lubricating oil is supplied, and details of the circumferential groove G1 will be described later.

The orbiting scroll 22 is a member that forms a compression chamber S1 with the fixed scroll 21 by its movement (orbiting), and is provided between the fixed scroll 21 and the frame 23. As shown in fig. 1, the orbiting scroll 22 includes a mirror plate 22a, an orbiting scroll 22b, and a boss portion 22c. The mirror plate 22a is a portion that slides between the mirror plate surface 21f of the fixed scroll 21, and has a disk shape. The orbiting scroll 22b (see also fig. 3) is a member forming the compression chamber S1 together with the fixed scroll 21b, and has a scroll shape. The boss portion 22c is a portion fitted to the eccentric portion 3b of the crankshaft 3, and is cylindrical. As shown in fig. 1, the swivel overlap 22b extends upward from the mirror plate 22 a. On the other hand, the boss portion 22c extends downward from the mirror plate 22 a.

The scroll-like fixed overlap 21b is engaged with the scroll-like orbiting overlap 22b, and a compression chamber S1 is formed between the fixed overlap 21b and the orbiting overlap 22 b. The compression chamber S1 is a space for compressing the gaseous refrigerant, and is formed on the outer line side and the inner line side of the swivel joint 22b, respectively. Further, a discharge port J2 is provided near the center of the platen 21a of the fixed scroll 21. The discharge port J2 is an opening for guiding the refrigerant compressed in the compression chamber S1 to the space S3 above the compression mechanism 2.

The frame 23 is a member for supporting the fixed scroll 21. The frame 23 has a substantially rotationally symmetrical shape and is fixed to the inner peripheral wall of the cylinder chamber 1 a. The frame 23 is provided with an insertion hole H1 through which the crankshaft 3 is inserted.

A back pressure chamber S4 is provided between the orbiting scroll 22 and the frame 23. For example, when the gaseous refrigerant is compressed with a decrease in the volume of the compression chamber S1, a downward force is generated to pull the orbiting scroll 22 away from the fixed scroll 21. Therefore, the orbiting scroll 22 is pushed up toward the fixed scroll 21 by the pressure of the back pressure chamber S4. The pressure of the back pressure chamber S4 is generally a predetermined intermediate pressure between the suction pressure and the discharge pressure of the scroll compressor 100.

The term "back pressure" included in the back pressure chamber S4 is not particularly limited to the level of the pressure in the back pressure chamber S4. The pressure in the back pressure chamber S4 is usually a value between the suction pressure and the discharge pressure, but may be temporarily substantially equal to the discharge pressure in some cases.

As shown in fig. 1, a seal ring R1 is provided in an annular groove (reference numeral not shown) provided inside the frame 23. The seal ring R1 is compressed by the lower surface of the boss portion 22c, and the space inside and outside the boss portion 22c in the radial direction is partitioned. Further, the radially inner side of the boss portion 22c becomes a high-pressure space substantially equal to (or slightly lower than) the discharge pressure. The radially outer side of the boss portion 22c is normally a back pressure chamber S4 having an intermediate pressure lower than the discharge pressure.

The crankshaft 3 (shaft) shown in fig. 1 is a shaft that rotates integrally with the rotor 4b of the motor 4, and extends in the up-down direction. As shown in fig. 1, the crankshaft 3 includes a main shaft portion 3a, an eccentric portion 3b extending upward from the main shaft portion 3a, and an oil feed member 3c provided at a lower end of the main shaft portion 3 a. The main shaft 3a is coaxially fixed to a rotor 4b of the motor 4, and rotates integrally with the rotor 4 b. The eccentric portion 3b is a portion that rotates eccentrically with respect to the main shaft portion 3a, and is fitted into the boss portion 22c of the orbiting scroll 22 as described above. The eccentric portion 3b rotates while being eccentric, and thereby the orbiting scroll 22 orbits.

The oil supply member 3c is a centrifugal pump that sucks the lubricating oil from the oil reservoir E1 of the closed casing 1, and is provided at the lower end of the main shaft portion 3 a. An opening 3h for guiding the lubricating oil to the inside is provided at the lower end of the oil feed 3 c. In addition to the centrifugal force accompanying the rotation of the oil feed 3c, the lubricating oil is sucked up through the oil feed 3c and the oil feed through hole 3d in order by the pressure difference between the upper and lower portions of the oil feed through hole 3d. In this way, by providing the oil feed member 3c (centrifugal pump) near the lower end of the crankshaft 3 (shaft), the supply of the lubricating oil through the oil feed through hole 3d is promoted. A predetermined metal (not shown) that rotates together with the crankshaft 3 may be provided inside the crankshaft 3.

As shown in fig. 1, the crankshaft 3 has an oil supply through hole 3d through which lubricating oil flows. The oil supply through hole 3d communicates with the interior of the oil supply 3c, and opens to the upper portion of the crankshaft 3. The oil supply through hole 3d branches off in a predetermined manner so as to supply the lubricating oil to the main bearing 5, the rotating bearing 6, and the like as well.

The motor 4 is a drive source for rotating the crankshaft 3, and is provided between the frame 23 and the subframe 9. As shown in fig. 1, the motor 4 includes a stator 4a and a rotor 4b. The stator 4a is fixed to the inner peripheral wall of the cylinder chamber 1 a. The rotor 4b is rotatably disposed radially inward of the stator 4 a. The crankshaft 3 is fixed to the rotor 4b coaxially with a central axis (not shown).

The main bearing 5 rotatably supports an upper portion of the main shaft portion 3a with respect to the frame 23, and is provided on a peripheral wall surface of the insertion hole H1 of the frame 23. The orbiting bearing 6 rotatably supports the eccentric portion 3b with respect to the boss portion 22c of the orbiting scroll 22, and is provided on the inner peripheral surface of the boss portion 22 c.

The cross ring 7 is a wheel-shaped member that makes the orbiting scroll 22 not to revolve by the eccentric rotation of the eccentric portion 3 b. The cross ring 7 is attached to a groove (not shown) in the lower surface of the orbiting scroll 22 and to a groove (not shown) in the frame 23. The balance weight 8 is a member for suppressing vibration of the scroll compressor 100. In the example of fig. 1, a balance weight 8 is provided on the upper side of the rotor 4b in the main shaft portion 3a of the crankshaft 3. Further, another balance weight (not shown) may be provided on the rotor 4b of the motor 4.

The sub-frame 9 is a member rotatably supporting the lower portion of the main shaft 3 a. As shown in fig. 1, the sub-frame 9 is fixed to the closed casing 1 in a state of being disposed below the motor 4. The subframe 9 is provided with a hole (reference numeral not shown) through which the crankshaft 3 is inserted. Further, a sub bearing 9a is provided on the peripheral wall surface of the hole of the sub frame 9. The sub-bearing 9a rotatably supports the lower portion of the main shaft 3a with respect to the sub-frame 9.

The power supply terminal 10 is a terminal for supplying electric power to the motor 4, and is electrically connected to the motor 4 via a wiring. A plurality of legs 11 support the closed casing 1 and are provided in the bottom chamber 1c.

When the crankshaft 3 is rotated by the drive of the motor 4, the orbiting scroll 22 orbits accordingly. Then, the compression chambers S1 formed in this order are contracted, and the gaseous refrigerant is compressed. The compressed refrigerant is discharged to the space S3 above the compression mechanism 2 through the discharge port J2 of the fixed scroll 21. The refrigerant discharged to the space S3 in this way is guided to the motor chamber S5 through a flow path (not shown) between the compression mechanism 2 and the closed casing 1, and is discharged to the outside through the discharge pipe P2.

The lubricating oil stored as the oil reservoir E1 at the bottom of the closed casing 1 rises from the oil feed 3c of the crankshaft 3 through the oil feed through hole 3d, and lubricates the sub-bearing 9a, the main bearing 5, the swivel bearing 6, and the like. The lubricating oil that has reached the opening (not shown) in the upper end of the oil supply through hole 3d is guided to the oil supply passage 12 (see also fig. 2) of the orbiting scroll 22 described later.

Fig. 2 is a longitudinal sectional view of the orbiting scroll 22 provided in the scroll compressor.

As shown in fig. 2, the orbiting scroll 22 is provided with an oil supply passage 12. The oil supply passage 12 is a passage for guiding the lubricating oil from the oil supply through hole 3d of the crankshaft 3 (see fig. 1) to the mirror plate surface 21f side of the fixed scroll 21 (see fig. 1). The oil supply passage 12 is configured to include a passage H3, a communication hole H2, and an oil supply hole H4.

As shown in fig. 2, a communication hole H2 is provided in the mirror plate 22a in the lateral direction (the direction parallel to the upper and lower surfaces of the mirror plate 22 a). The communication hole H2 is formed by, for example, performing predetermined cutting from the peripheral wall surface of the end plate 22a to the radially inner side. The end of the communication hole H2 on the outer peripheral side is sealed by a seal plug N1. As shown in fig. 2, the upstream side (radially inner side) of the communication hole H2 communicates with the space radially inner of the boss portion 22c via a relatively short flow path H3 in the up-down direction. In addition, the downstream side (radially outer side) of the communication hole H2 communicates with the oil supply hole H4 in the up-down direction. The high-pressure lubricating oil supplied through the oil supply through hole 3d (see fig. 1) of the crankshaft 3 is guided to the circumferential groove G1 (see fig. 4) of the fixed scroll 21 through the flow path H3, the communication hole H2, and the oil supply hole H4 in this order.

Fig. 3 is a perspective view of the orbiting scroll 22 provided in the scroll compressor.

As described above, the orbiting scroll 22 includes the circular plate-shaped mirror plate 22a, the scroll-shaped orbiting scroll 22b, and the cylindrical boss portion 22c (see fig. 2). A seal plug N1 closing an end portion on the outer peripheral side of the communication hole H2 is fitted to the peripheral wall of the mirror plate 22a of the orbiting scroll 22. The mirror surface 22d of the orbiting scroll 22 is provided with an oil drain groove G2 in addition to the opening J4 provided with the oil supply hole H4 (see fig. 2). The oil discharge groove G2 is a groove intermittently communicating with the circumferential groove G1 (see fig. 4) of the fixed scroll 21. In the example of fig. 3, the oil drain groove G2 is provided in the radial direction from a predetermined position of the mirror plate surface 22d of the orbiting scroll 22 to the edge of the mirror plate surface 22 d. Then, the opening J4 of the oil supply hole H4 (see fig. 2) and the oil discharge groove G2 move in a predetermined manner in association with the orbiting of the orbiting scroll 22. The oil discharge groove G2 is always in communication with the back pressure chamber S4 (see fig. 1) regardless of the position of the orbiting scroll 22.

As described above, the pressure in the back pressure chamber S4 (see fig. 1) acts as a force that pushes up the orbiting scroll 22 toward the fixed scroll 21. However, for example, under an operating condition of a high compression ratio, if the thrust load between the fixed scroll 21 and the orbiting scroll 22 becomes excessively large, there is a possibility that friction loss increases and sintering occurs on the sliding surface. Therefore, in the first embodiment, an arcuate circumferential groove G1 (see fig. 4) is provided on the outer side of the fixed scroll 21 on the mirror plate surface 21f (see fig. 4) and the fixed lap 21b (see fig. 4), and high-pressure lubricating oil is guided to the circumferential groove G1. This can appropriately suppress the thrust load between the fixed scroll 21 and the orbiting scroll 22.

Fig. 4 is a bottom view of the fixed scroll 21 provided in the scroll compressor.

As described above, the fixed scroll 21 has a structure in which the fixed scroll 21b having a spiral shape is provided on the platen 21 a. As shown in fig. 4, a circumferential groove G1 is provided in the mirror plate surface 21f of the fixed scroll 21. The circumferential groove G1 is a groove in which high-pressure lubricating oil is intermittently supplied via the oil supply passage 12 (see fig. 2) of the orbiting scroll 22 (see fig. 2). As shown in fig. 4, the circumferential groove G1 includes an arc portion G11 and a communication portion G12. The circular arc portion G11 is a circular arc-shaped groove provided on the mirror plate surface 21f of the fixed scroll 21. The circular arc portion G11 is formed in a range of 30 ° to 350 ° in its center angle with respect to, for example, the vicinity of the center (center of the circular arc) when the scroll 21 is fixed in bottom view.

At least a part of the circular arc portion G11 may overlap with a predetermined partial load region. Here, the offset load region is a region where the mirror plate surface 22d (see fig. 3) of the orbiting scroll 22 is particularly strongly in contact with the mirror plate surface 21f of the fixed scroll 21 when a force (a resultant force of centrifugal force and gas load) tilting the orbiting scroll 22 (see fig. 1) acts on the mirror plate surface 21f of the fixed scroll 21. In the first embodiment, the high-pressure lubricating oil is intermittently supplied to the circumferential groove G1 including the circular arc portion G11, and thereby the force acts to separate the orbiting scroll 22 from the fixed scroll 21. Accordingly, the thrust load between the orbiting scroll 22 and the fixed scroll 21 is moderately reduced, and therefore friction loss and seizing at the sliding surface can be suppressed.

The communication portion G12 is a portion intermittently communicating with the oil supply passage 12 (see fig. 2), and is connected to one end of the circular arc portion G11. More specifically, in the circumferential groove G1, a communication portion G12 is provided on the opposite side of the end portion G11a on the side intermittently communicating with the oil drain groove G2 (see fig. 3) of the orbiting scroll 22. Then, with the movement of the orbiting scroll 22 (see fig. 1), the communication portion G12 of the circumferential groove G1 intermittently communicates with the oil supply passage 12 (see fig. 2), and the high-pressure lubricating oil having substantially the same discharge pressure is guided to the circumferential groove G1. The diameter of the opening J4 (see fig. 2) of the oil supply passage 12 (see fig. 2) may be equal to the groove width of the communication portion G12, or may be different from the groove width of the communication portion G12.

Fig. 5 is an explanatory view showing a movement locus M4 of the opening J4 of the oil supply flow path by partially enlarging the region K1 in fig. 4.

In fig. 5, a movement locus M4 of an opening J4 of the oil supply passage 12 (see fig. 2) provided on the upper surface of the orbiting scroll 22 is indicated by a single-dot chain line. As described above, high-pressure lubricating oil is intermittently supplied to the circumferential groove G1 from the oil supply through hole 3d (see fig. 1) of the crankshaft 3 via the oil supply flow path 12 (see fig. 2). In the example of fig. 5, with the orbiting scroll 22 (see fig. 2), the oil supply passage 12 communicates with the circumferential groove G1 twice before the opening J4 of the oil supply passage 12 (see fig. 2) returns to the original position by the circular movement locus M4. The communication portion G12 is formed to partially include the movement locus M4 of the opening J4 on the mirror plate surface 21f (see fig. 4) side in the oil supply flow path 12 (see fig. 2). By appropriately adjusting the position and length of the communication portion G12 in the design stage, an appropriate amount of lubricating oil can be intermittently supplied to the circumferential groove G1.

Fig. 6A is an explanatory view of a state in which the opening J4 of the oil supply passage of the orbiting scroll is not in communication with the circumferential groove G1, and the oil discharge groove G2 is not in communication with the circumferential groove G1.

In fig. 6A, the annular sliding surfaces V1 of the fixed scroll 21 and the orbiting scroll 22 (see fig. 3) are indicated by dots. In fig. 6A, the opening J4 (see also fig. 2) of the oil supply passage 12 (see also fig. 2) of the orbiting scroll 22 and the oil drain groove G2 (see also fig. 3) are projected onto the fixed scroll 21. In the state of fig. 6A, the opening J4 is not yet in communication with the circumferential groove G1 during the movement of the orbiting scroll 22, and the oil drain groove G2 is not in communication with the circumferential groove G1. By providing such a non-communication section, wasteful supply of a large amount of lubricating oil to the circumferential groove G1 can be suppressed. Therefore, a large amount of lubricating oil can be prevented from flowing into the compression chamber S1 from the circumferential groove G1 (see fig. 1), and further, heating loss of the refrigerant can be prevented. That is, the amount of refrigerant in the compression chamber S1 can be suppressed from decreasing (the freezing capacity decreases) due to expansion associated with a temperature increase of the refrigerant. After the state shown in fig. 6A, the positions of the opening J4 and the oil drain groove G2 are changed in the order of fig. 6B, 6C, and 6D.

Fig. 6B is an explanatory diagram of a state in which the opening J4 of the oil supply flow path of the orbiting scroll communicates with the circumferential groove G1 and the oil drain groove G2 communicates with the circumferential groove G1.

In the state shown in fig. 6B, the opening J4 of the oil supply flow path 12 (refer to fig. 2) of the orbiting scroll 22 communicates with the circumferential groove G1, and the oil drain groove G2 also communicates with the circumferential groove G1. Thereby, the high-pressure lubricating oil having substantially the same discharge pressure is supplied to the circumferential groove G1 via the oil supply passage 12 (see fig. 2). In addition, it is preferable that the oil drain groove G2 communicates with the circumferential groove G1 at the start of communication of the oil supply flow path 12 with the circumferential groove G1. As a result, the high-pressure lubricating oil such as the refrigerant gas existing in the circumferential groove G1 is pushed out to the back pressure chamber S4 (see fig. 1) through the oil drain groove G1b, and therefore the lubricating oil easily flows into the circumferential groove G1.

By flowing the high-pressure lubricating oil into the circumferential groove G1, the thrust load between the fixed scroll 21 and the orbiting scroll 22 can be reduced. Further, the lubricating oil is appropriately supplied from the circumferential groove G1 to the compression chamber S1 (see fig. 1) through a minute gap between the mirror plate surface 21f (see fig. 4) of the fixed scroll 21 and the mirror plate 22a (see fig. 1) of the orbiting scroll 22. As a result, the fixed overlap 21b (see fig. 1), the swivel overlap 22b (see fig. 1), and the like are lubricated, and therefore wear and seizure can be suppressed. Further, by supplying the lubricating oil to the back pressure chamber S4 (see fig. 1) through the oil drain groove G2, the sliding portions of the back pressure chamber S4 are sufficiently lubricated.

Further, by supplying the lubricating oil from the circumferential groove G1 to the compression chamber S1 (see fig. 1) of relatively low pressure, the pressure (discharge pressure) of the upper portion of the oil supply through hole 3d in the crankshaft 3 (see fig. 1) is lower than the pressure (discharge pressure) of the lower portion of the oil supply through hole 3 d. That is, a pressure difference is generated between the upper and lower portions of the crankshaft 3. By such a pressure difference, even when the scroll compressor 100 is operated at a low speed, the lubricating oil is sucked up from the oil reservoir E1 (see fig. 1) through the oil supply through hole 3 d. Therefore, it is not particularly necessary to use a gear pump (not shown) such as a trochoid pump, and it is only necessary to provide the oil supply unit 3c (centrifugal pump: see fig. 1) having a simple structure, so that the manufacturing cost of the scroll compressor 100 can be reduced.

Fig. 6C is an explanatory diagram of a state immediately after the end of communication between the oil drain groove G2 and the circumferential groove G1.

As shown in fig. 6C, immediately after the oil drain groove G2 is separated from the circumferential groove G1, the opening J4 of the oil supply flow path 12 (see fig. 2) communicates with the circumferential groove G1. In other words, while the oil supply passage 12 (see fig. 2) communicates with the circumferential groove G1, the communication between the oil drain groove G2 and the circumferential groove G1 ends. As a result, in a state where the outlet of the lubricating oil in the circumferential groove G1 (the end portion G11a shown in fig. 4) is blocked, the high-pressure lubricating oil flows in through the oil supply passage 12 (see fig. 2). As a result, the circumferential groove G1 is filled with the high-pressure lubricating oil having substantially the same discharge pressure, and therefore the thrust load between the fixed scroll 21 and the orbiting scroll 22 (see fig. 1) can be sufficiently reduced.

Fig. 6D is an explanatory diagram of a state immediately after the end of communication between the opening J4 of the oil supply flow path of the swirl overlap and the circumferential groove G1.

As shown in fig. 6D, immediately after the opening J4 of the oil supply passage 12 (see fig. 2) is separated from the circumferential groove G1, the oil drain groove G2 is also separated from the circumferential groove G1. Thereby, the circumferential groove G1 is maintained in a state filled with the high-pressure lubricating oil.

Fig. 7 is a timing chart showing a communication state of the circumferential groove.

In fig. 7, the horizontal axis represents time, and the vertical axis represents a communication state of the circumferential groove G1 (see fig. 4). The solid line graph of fig. 7 shows a communication state between the circumferential groove G1 (see fig. 4) and the oil drain groove G2 (see fig. 3). The single-dot chain line chart of fig. 7 shows a communication state between the circumferential groove G1 (see fig. 4) and the oil supply flow path 12 (see fig. 2).

As shown in the solid line chart of fig. 7, the communication between the circumferential groove G1 (see fig. 4) and the oil drain groove G2 (see fig. 3) is alternately repeated in time. As shown by the one-dot chain line chart of fig. 7, the communication and non-communication between the circumferential groove G1 (see fig. 4) and the oil supply flow path 12 (see fig. 2) are alternately repeated in time. That is, the circumferential groove G1 intermittently communicates with the oil drain groove G2, and intermittently communicates with the oil supply flow path 12.

In the example of fig. 7, the circumferential groove G1 and the oil drain groove G1b are in a non-communication state from time t0 to t1, and the circumferential groove G1 and the oil supply passage 12 are also in a non-communication state (state of fig. 6A). At a later time t1, communication between the circumferential groove G1 and the oil drain groove G2 is started, and further, at a time t2, communication between the circumferential groove G1 and the oil supply flow path 12 is started (state of fig. 6B). Further, at time t3, the communication between the circumferential groove G1 and the oil drain groove G2 ends (the state of fig. 6C), and further, at time t4, the communication between the circumferential groove G1 and the oil supply passage 12 ends (the state of fig. 6D).

In addition, the opening J4 of the oil supply flow path 12 (see fig. 2) communicates with the circumferential groove G1 twice during one revolution around the circular movement locus M4 (see fig. 5), but in fig. 7, illustration of the second communication (communication at the circular arc portion G11 of fig. 5) is omitted. When the circumferential groove G1 communicates with the oil supply passage 12 for the 2 nd time, the circumferential groove G1 and the oil drain groove G2 may be in a non-communicating state.

< Effect >

According to the first embodiment, as shown in fig. 6C, while the opening J4 of the oil supply flow path 12 (refer to fig. 2) communicates with the circumferential groove G1, the communication of the oil drain groove G2 with the circumferential groove G1 ends. This maintains the state in which the circumferential groove G1 is filled with high-pressure lubricating oil from the end of communication between the oil drain groove G2 and the circumferential groove G1 to the start of the next communication. Therefore, the orbiting scroll 22 (see fig. 3) can be prevented from strongly hitting the fixed scroll 21 in the vicinity of the circumferential groove G1, and further friction loss and seizing at the sliding surface can be prevented. Further, since the lubricating oil is appropriately supplied to the sliding portions of the compression chamber S1 (see fig. 1) and the back pressure chamber S4 (see fig. 1), the reliability of the scroll compressor 100 is improved.

Further, the circumferential groove G1 of the fixed scroll 21 intermittently communicates with the opening J4 of the oil supply passage 12, thereby generating a pressure difference between the upper and lower portions of the oil supply through hole 3d of the crankshaft 3. Thus, even when the scroll compressor 100 is operated at a low speed, the lubricant is sucked up through the lubricant supply through hole 3d (see fig. 1), and thus, the shortage of lubrication can be suppressed. In addition, since a centrifugal pump can be used as the oil supply 3c (see fig. 1), the manufacturing cost of the scroll compressor 100 can be reduced.

In addition, according to the first embodiment, since the oil drain groove G2 (see fig. 6B) intermittently communicates with the back pressure chamber S4 (see fig. 1), even when foreign matter such as abrasion powder enters the circumferential groove G1 (see fig. 6B), the foreign matter is discharged through the oil drain groove G2. Therefore, clogging of the circumferential groove G1 with foreign matter can be suppressed, and further, the oil supply effect of supplying oil to each sliding portion via the circumferential groove G1 can be maintained for a long period of time.

In addition, since the back pressure chamber S4 is often at a higher pressure than the compression chamber S1, the amount of oil supplied to the back pressure chamber S4 is likely to be insufficient in the scroll compressor of the related art. For example, if the amount of oil supplied to the back pressure chamber S4 is to be increased, the amount of oil supplied to the compression chamber S1 excessively increases, and therefore, a heating loss of the refrigerant occurs, resulting in a decrease in the cooling capacity. In contrast, in the first embodiment, the circumferential groove G1 (see fig. 4) intermittently communicates with the discharge chamber S4 (see fig. 1), so that the amount of oil supplied to the back pressure chamber S4 can be increased without particularly increasing the amount of oil supplied to the back pressure chamber S1 (see fig. 1). Thereby, lubrication of each sliding portion of the back pressure chamber S4 is promoted.

Second embodiment

The second embodiment differs from the first embodiment in that an oil drain groove is not particularly provided in the orbiting scroll 22A (see fig. 8), and an oil drain groove GA2 (see fig. 9) is provided in the mirror plate surface 21Af of the fixed scroll 21A. The second embodiment is different from the first embodiment in that a circumferential groove G1 (see fig. 9) of the fixed scroll 21A is connected to an oil drain groove GA2 (see fig. 9), and the oil drain groove GA2 is intermittently communicated with a back pressure chamber S4 (see fig. 1). The other components (overall structure of the scroll compressor, etc.: refer to fig. 1) are the same as those of the first embodiment. Therefore, a description will be given of a portion different from the first embodiment, and a description will be omitted for a repeated portion.

Fig. 8 is a perspective view of an orbiting scroll 22A provided in the scroll compressor of the second embodiment.

The orbiting scroll 22A shown in fig. 8 includes a circular plate-shaped mirror plate 22Aa, a scroll-shaped orbiting scroll 22b, and a cylindrical boss portion 22c (see fig. 1). An opening J4 of the oil supply flow path 12 (see fig. 2) is provided in the mirror surface 22Ad of the orbiting scroll 22A. Then, the opening J4 of the oil supply passage 12 (see fig. 2) moves in a predetermined manner in association with the orbiting of the orbiting scroll 22A. The mirror plate surface 22Ad of the orbiting scroll 22A is not particularly provided with an oil drain groove, and the mirror plate surface 21Af (see fig. 9) of the fixed scroll 21A described later is provided with an oil drain groove GA2 (see fig. 9).

Fig. 9 is a bottom view of a fixed scroll 21A provided in the scroll compressor.

As shown in fig. 9, a mirror plate surface 21fA of the fixed scroll 21A is provided with a circumferential groove G1 and an oil drain groove GA2. The circumferential groove G1 is a groove in which high-pressure lubricating oil is intermittently supplied via the oil supply passage 12 (see fig. 2) of the orbiting scroll 22 (see fig. 2). The oil drain groove GA2 is a groove intermittently communicating with the back pressure chamber S4 (see fig. 1). As shown in fig. 9, the oil drain groove GA2 is connected to the opposite side of the communication portion G12 in the circumferential groove G1.

Fig. 10A is an explanatory view of a state in which the opening J4 of the oil supply passage of the orbiting scroll is not communicated with the circumferential groove G1, and the oil discharge groove GA2 is not communicated with the back pressure chamber.

In fig. 10A, the annular sliding surface V1 of the fixed scroll 21A and the orbiting scroll 22 (see fig. 3) is indicated by dots. In fig. 10A, the opening J4 (see also fig. 3) of the oil supply passage 12 of the orbiting scroll 22 is projected onto the fixed scroll 21A. In the state of fig. 10A, the opening J4 is not yet in communication with the circumferential groove G1 during the movement of the orbiting scroll 22, and the oil drain groove GA2 is not in communication with the back pressure chamber S4 (see fig. 1). By providing such a non-communication section, wasteful supply of a large amount of lubricating oil to the circumferential groove G1 can be suppressed. After the state shown in fig. 10A, the position of the opening J4 is changed in the order of fig. 10B, 10C, and 10D.

Fig. 10B is an explanatory diagram of a state in which the opening J4 of the oil supply flow path of the orbiting scroll communicates with the circumferential groove G1 and the oil drain groove GA2 communicates with the back pressure chamber.

In the state shown in fig. 10B, the opening J4 of the oil supply passage 12 (see fig. 2) of the orbiting scroll 22 communicates with the circumferential groove G1, and the oil drain groove GA2 also communicates with the back pressure chamber S4 (see fig. 1). That is, the oil drain groove GA2 communicates with the back pressure chamber S4 (see fig. 1) via a portion of the radially outer end portion of the oil drain groove GA2 exposed from the annular sliding surface V1. Thereby, the high-pressure lubricating oil having substantially the same discharge pressure is supplied to the circumferential groove G1 via the oil supply passage 12 (see fig. 2). Further, at the start of communication between the oil supply passage 12 (see fig. 2) and the circumferential groove G1, it is preferable that the oil drain groove GA2 communicates with the back pressure chamber S4 (see fig. 1). As a result, the high-pressure lubricating oil such as the refrigerant GAs existing in the circumferential groove G1 is pushed out to the back pressure chamber S4 (see fig. 1) through the oil drain groove GA2, and therefore the lubricating oil easily flows into the circumferential groove G1.

Fig. 10C is an explanatory diagram of a state immediately after the communication between the oil drain groove GA2 and the back pressure chamber is completed.

As shown in fig. 10C, the radially outer end of the oil drain groove GA2 enters the inside of the annular sliding surface V1, and communication between the oil drain groove GA2 and the back pressure chamber S4 (see fig. 1) ends. Immediately after the communication between the oil drain groove GA2 and the back pressure chamber S4 is completed, the opening J4 of the oil supply passage 12 (see fig. 2) is in communication with the circumferential groove G1. In other words, while the oil supply passage 12 (see fig. 2) communicates with the circumferential groove G1, the communication between the oil drain groove GA2 and the back pressure chamber S4 (see fig. 1) is ended. As a result, in a state where the outlet of the lubricating oil in the circumferential groove G1 is blocked, the high-pressure lubricating oil flows in through the oil supply passage 12 (see fig. 2). As a result, the circumferential groove G1 is filled with the high-pressure lubricating oil having substantially the same discharge pressure, and therefore the thrust load between the fixed scroll 21A and the orbiting scroll 22 (see fig. 1) can be sufficiently reduced.

Fig. 10D is an explanatory view of a state immediately after the end of communication between the opening J4 of the oil supply passage of the orbiting scroll and the circumferential groove G1.

As shown in fig. 10D, immediately after the opening J4 of the oil supply passage 12 (see fig. 2) is separated from the circumferential groove G1, the oil drain groove GA2 is not communicated with the back pressure chamber S4 (see fig. 1). Thereby, the circumferential groove G1 is maintained in a state filled with the high-pressure lubricating oil.

The state of communication between the circumferential groove G1 (see fig. 9) and the oil supply flow path 12 (see fig. 2) and the state of communication between the oil drain groove GA2 (see fig. 9) and the back pressure chamber S4 (see fig. 1) may be shifted in the same manner as in fig. 7. In this case, the solid line chart of fig. 7 is replaced with a chart showing the communication state between the oil drain groove GA2 and the back pressure chamber S4. Note that, the single-dot chain line chart of fig. 7 shows a communication state between the circumferential groove G1 and the oil supply passage 12, as in the first embodiment.

< Effect >

According to the second embodiment, as shown in fig. 10C, while the opening J4 of the oil supply passage 12 (see fig. 2) communicates with the circumferential groove G1, the communication between the oil drain groove GA2 and the back pressure chamber S4 (see fig. 1) is ended. Thus, the state in which the circumferential groove G1 is filled with the high-pressure lubricating oil is maintained from the end of the communication between the oil drain groove GA2 and the back pressure chamber S4 to the start of the next communication. Therefore, the thrust load between the fixed scroll 21A and the orbiting scroll 22 can be moderately reduced.

In addition, according to the second embodiment, since the oil drain groove GA2 (see fig. 9) is intermittently communicated with the back pressure chamber S4 (see fig. 1), even when foreign matter such as abrasion powder enters the circumferential groove G1 (see fig. 9), the foreign matter is discharged through the oil drain groove GA 2. Therefore, clogging of the circumferential groove G1 with foreign matter can be suppressed, and further, the oil supply effect of supplying oil to each sliding portion via the circumferential groove G1 can be maintained for a long period of time.

Third embodiment

In the third embodiment, an air conditioner W1 (refrigeration cycle apparatus: see fig. 11) provided with the scroll compressor 100 (see fig. 1) described in the first embodiment will be described.

Fig. 11 is a block diagram of a refrigerant circuit Q1 including an air conditioner W1 according to the third embodiment.

The solid arrows in fig. 11 indicate the flow of the refrigerant during the heating operation.

On the other hand, the dashed arrow in fig. 11 indicates the flow of the refrigerant during the cooling operation.

The air conditioner W1 is an apparatus for performing air conditioning such as cooling and heating. As shown in fig. 11, the air conditioner W1 includes a scroll compressor 100, an outdoor heat exchanger 71, an outdoor fan 72, an expansion valve 73, a four-way valve 74, an indoor heat exchanger 75, and an indoor fan 76.

In the example of fig. 11, the scroll compressor 100, the outdoor heat exchanger 71, the outdoor fan 72, the expansion valve 73, and the four-way valve 74 are provided in the outdoor unit U1. The indoor heat exchanger 75 and the indoor fan 76 are provided in the indoor unit U2.

The scroll compressor 100 is a device for compressing a gaseous refrigerant, and has the same configuration as that of the first embodiment (see fig. 1). The outdoor heat exchanger 71 is a heat exchanger that exchanges heat between a refrigerant flowing through a heat pipe (not shown) thereof and outside air sent from the outdoor fan 72. The outdoor fan 72 is a fan that sends outside air to the outdoor heat exchanger 71. The outdoor fan 72 includes an outdoor fan motor 72a as a driving source, and is disposed in the vicinity of the outdoor heat exchanger 71.

The indoor heat exchanger 75 is a heat exchanger that exchanges heat between a refrigerant flowing through a heat pipe (not shown) thereof and indoor air (air in an air-conditioning room) fed from the indoor fan 76. The indoor fan 76 is a fan that sends indoor air to the indoor heat exchanger 75. The indoor fan 76 includes an indoor fan motor 76a as a driving source, and is provided in the vicinity of the indoor heat exchanger 75.

The expansion valve 73 is a valve for reducing the pressure of the refrigerant condensed by the "condenser" (one of the outdoor heat exchanger 71 and the indoor heat exchanger 75). The refrigerant decompressed by the expansion valve 73 is guided to an "evaporator" (the other of the outdoor heat exchanger 71 and the indoor heat exchanger 75).

The four-way valve 74 is a valve that switches the flow path of the refrigerant according to the operation mode of the air conditioner W1. For example, during the cooling operation (see the dashed arrow in fig. 11), in the refrigerant circuit Q1, the refrigerant circulates through the scroll compressor 100, the outdoor heat exchanger 71 (condenser), the expansion valve 73, and the indoor heat exchanger 75 (evaporator) in this order. On the other hand, during the heating operation (see the solid arrow in fig. 11), in the refrigerant circuit Q1, the refrigerant circulates through the scroll compressor 100, the indoor heat exchanger 75 (condenser), the expansion valve 73, and the outdoor heat exchanger 71 (evaporator) in this order.

< Effect >

According to the third embodiment, the air conditioner W1 includes the scroll compressor 100 having low manufacturing cost, high performance, and high reliability. This reduces the manufacturing cost of the entire air conditioner W1, and improves the performance and reliability thereof.

Modification of the invention

While the scroll compressor 100 and the air conditioner W1 according to the present invention have been described in the above embodiments, the present invention is not limited to these descriptions, and various modifications are possible. For example, the scroll compressor may be configured as shown in fig. 12 (first modification) and fig. 13 (second modification).

Fig. 12 is an explanatory diagram showing a movement trajectory M4 of an opening J4 of an oil supply flow path of an orbiting scroll in the scroll compressor of the first modification.

The region K2 shown in fig. 12 corresponds to the region K1 shown in fig. 4 (first embodiment). As shown in fig. 12, the circumferential groove GA1 includes a circular arc portion G11 and a communication portion G13. The communication portion G13 is formed as a part of the movement locus M4 including the opening J4 of the oil supply passage 12 (see fig. 2). As shown in fig. 12, the opening J4 may also communicate with the circumferential groove G1 once during one revolution of the opening J4 around the circular-shaped movement locus M4. In such a configuration, by properly adjusting the length of the communication portion G13 at the design stage, high-pressure lubricating oil can be properly supplied to the circumferential groove GA 1.

Fig. 13 is an explanatory diagram showing a movement trajectory M4 of an opening J4 of an oil supply flow path of an orbiting scroll in a scroll compressor of a second modification.

As shown in fig. 13, the end portion of the circumferential groove GB1 opposite to the oil drain groove G2 (see fig. 4) may be formed in a T shape. In such a configuration, by properly adjusting the length of the communication portion G14 at the design stage, high-pressure lubricating oil can be properly supplied to the circumferential groove GB 1. In the example of fig. 13, the opening J4 of the oil supply passage 12 (see fig. 2) is shown to communicate with the circumferential groove G1 times before the opening J4 returns to the original position around the circular movement locus M4 once, but may communicate 2 times. In such a configuration, the same effects as those of the first embodiment are also achieved.

In the embodiments, the circumferential groove G1 is described as being circular arc-shaped, but may be a predetermined shape other than circular arc-shaped.

In the first embodiment, the example in which the oil drain groove G2 (see fig. 4) is provided in the radial direction has been described, but the direction in which the oil drain groove G2 extends may be appropriately changed as long as the oil drain groove G2 communicates with the back pressure chamber S4 (see fig. 1). The same applies to the oil drain groove GA2 (see fig. 9) of the second embodiment.

The air conditioner W1 (see fig. 11) described in the third embodiment can be applied to various types of air conditioners such as a multi-air conditioner for a building, in addition to an indoor air conditioner and a central air conditioner. In the third embodiment, the air conditioner W1 (refrigeration cycle apparatus) including the scroll compressor 100 is described, but the present invention is not limited thereto. For example, the third embodiment can be applied to other "refrigeration cycle apparatuses" such as a refrigerator, a hot water supply machine, an air-conditioning hot water supply apparatus, a cooler, and a refrigerator.

In addition, the embodiments can be appropriately combined. For example, the second embodiment (see fig. 9) and the third embodiment (see fig. 11) may be combined, and the circumferential groove G1 and the oil drain groove GA2 may be provided in the mirror plate surface 21Af of the fixed scroll 21A as the configuration of the scroll compressor provided in the air conditioner W1 (third embodiment) (second embodiment).

In each of the embodiments, the case where the refrigerant is compressed by the scroll compressor 100 has been described, but the present invention is not limited thereto. That is, each embodiment can be applied to a case where a predetermined gas other than the refrigerant is compressed by the scroll compressor 100.

The embodiments are described in detail for the purpose of easily understanding the present invention, and are not limited to the configuration in which all the components described are necessarily provided. In addition, deletion, and substitution of other structures can be appropriately performed for a part of the structures of each embodiment.

The above-described mechanism and structure are not necessarily all mechanisms and structures on the product, but are considered to be necessary for explanation.

Claims (5)

1. A scroll compressor is characterized in that,

the device is provided with:

a closed container;

a motor having a stator and a rotor and accommodated in the closed container;

a shaft having an oil supply through hole through which lubricating oil flows and rotating integrally with the rotor;

a fixed scroll having a scroll-like fixed overlap;

an orbiting scroll having an orbiting scroll in a spiral shape, a compression chamber being formed between the fixed scroll and the orbiting scroll; and

A frame having an insertion hole of the shaft, supporting the fixed scroll,

a back pressure chamber is provided between the orbiting scroll and the frame,

the orbiting scroll is provided with an oil supply flow path for guiding the lubricating oil from the oil supply through hole to the mirror plate surface side of the fixed scroll,

a circumferential groove intermittently communicating with the oil supply flow path is provided in the mirror plate surface of the fixed scroll,

the circumferential groove is not in communication with the suction inlet of the fixed scroll,

an oil drain groove communicated with the back pressure chamber is arranged on the mirror surface of the orbiting scroll,

the oil drain groove is intermittently communicated with the circumferential groove,

at the beginning of the communication of the oil supply flow path with the circumferential groove, the oil drain groove communicates with the circumferential groove,

during the period in which the oil supply flow path communicates with the circumferential groove, the communication between the oil drain groove and the circumferential groove ends.

2. A scroll compressor is characterized in that,

the device is provided with:

a closed container;

a motor having a stator and a rotor and accommodated in the closed container;

a shaft having an oil supply through hole through which lubricating oil flows and rotating integrally with the rotor;

A fixed scroll having a scroll-like fixed overlap;

an orbiting scroll having an orbiting scroll in a spiral shape, a compression chamber being formed between the fixed scroll and the orbiting scroll; and

a frame having an insertion hole of the shaft, supporting the fixed scroll,

a back pressure chamber is provided between the orbiting scroll and the frame,

the orbiting scroll is provided with an oil supply flow path for guiding the lubricating oil from the oil supply through hole to the mirror plate surface side of the fixed scroll,

the mirror plate surface of the fixed scroll is provided with a circumferential groove intermittently communicating with the oil supply flow path, and an oil drain groove connected to the circumferential groove,

the circumferential groove is not in communication with the suction inlet of the fixed scroll,

the oil drain groove is intermittently communicated with the back pressure chamber,

at the start of communication of the oil supply flow path with the circumferential groove, the oil drain groove communicates with the back pressure chamber,

during the period in which the oil supply flow path communicates with the circumferential groove, the communication between the oil drain groove and the back pressure chamber ends.

3. A scroll compressor according to claim 1 or 2, wherein,

The circumferential groove has an arc portion having an arc shape and a communication portion intermittently communicating with the oil supply flow path,

the communication portion is connected to the circular arc portion and is formed to partially include a movement locus of an opening of the oil supply passage on the mirror plate surface side of the fixed scroll.

4. A scroll compressor according to claim 1 or 2, wherein,

comprises a centrifugal pump provided near the lower end of the shaft,

the oil supply through hole opens at an upper portion of the shaft.

5. A refrigeration cycle apparatus, characterized in that,

a scroll compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger according to claim 1 or 2.