JP7213382B1 - Scroll compressor and refrigeration cycle device - Google Patents

Abstract

A highly reliable scroll compressor and the like are provided. 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 an end plate surface 21f side of a fixed scroll 21, and the end plate surface 21f of the fixed scroll 21 has an arc-shaped and an oil drain groove G1b connected to one end of the circumferential groove G1a are provided, and the oil drain groove G1b communicates with the back pressure chamber. The area is smaller than the channel area of the circumferential groove G1a, and the oil supply channel and the circumferential groove G1a intermittently communicate with each other. [Selection drawing] Fig. 4

Description

The present invention relates to scroll compressors and the like.

Regarding scroll compressors, for example, the technique described in Patent Document 1 is known as a technique for keeping the thrust load (force in the axial direction) from one of the fixed scroll and the orbiting scroll to the other within an appropriate range. That is, Patent Literature 1 describes forming an oil groove extending in the circumferential direction on the thrust sliding surface of the fixed scroll, and communicating the end of the oil groove with the negative pressure region.

JP 2016-20664 A

In the technique described in Patent Document 1, since the oil grooves of the fixed scroll are always in communication with the negative pressure region, the pressure of the lubricating oil in the oil grooves tends to decrease, and the thrust load may not be sufficiently reduced. Therefore, 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.

In order to solve the above-described problems, a scroll compressor according to the present invention has a closed container, a stator and a rotor, an electric motor housed in the closed container, and an oil supply through hole through which lubricating oil flows. and a shaft that rotates integrally with the rotor, a fixed scroll having a spiral fixed wrap, and a spiral orbital wrap, and a compression chamber is formed between the fixed wrap and the orbital wrap. An orbiting scroll and a frame having an insertion hole for the shaft and supporting the fixed scroll are provided, a back pressure chamber is provided between the orbiting scroll and the frame, and the orbiting scroll includes: An oil supply passage is provided for guiding lubricating oil from the oil supply through hole to the end plate surface side of the fixed scroll. a connecting oil drain groove is provided, the oil drain groove communicates with the back pressure chamber, and the flow area of the oil drain groove is smaller than the flow area of the circumferential groove. , the oil supply passage and the circumferential groove intermittently communicate with each other, the circumferential groove having an arc portion having an arc shape and a communication portion intermittently communicating with the oil supply passage; The communicating portion is connected to the arc portion on the side opposite to the oil drain groove, and is formed so as to partially include the locus of movement of the opening of the oil supply passage on the side of the end plate surface. The paths alternately communicate with the communicating portions and the arc portions included in one circumferential groove .

ADVANTAGE OF THE INVENTION According to this invention, a highly reliable scroll compressor etc. can be provided.

1 is a longitudinal sectional view of a scroll compressor according to a first embodiment; FIG. FIG. 2 is a vertical cross-sectional view of an orbiting scroll included in the scroll compressor according to the first embodiment; 1 is a perspective view of an orbiting scroll included in a scroll compressor according to a first embodiment; FIG. It is a bottom view of a fixed scroll with which the scroll compressor concerning a 1st embodiment is provided. FIG. 3 is a cross-sectional view of the vicinity of an oil drain groove in a fixed scroll and an orbiting scroll of the scroll compressor according to the first embodiment; FIG. 5 is an explanatory diagram showing the locus of movement of the opening of the oil supply passage by partially enlarging the region K1 in FIG. 4 in the scroll compressor according to the first embodiment; FIG. 5 is an explanatory diagram of a state in which the opening of the oil supply passage of the orbiting scroll does not communicate with the circumferential groove of the fixed scroll in the scroll compressor according to the first embodiment; FIG. 6 is an explanatory diagram of a state in which the opening of the oil supply passage of the orbiting scroll communicates with the circumferential groove of the fixed scroll in the scroll compressor according to the first embodiment; FIG. 5 is an explanatory diagram of a state in which the opening of the oil supply passage of the orbiting scroll does not communicate with the circumferential groove of the fixed scroll in the scroll compressor according to the first embodiment; FIG. 4 is a time chart showing communication states of oil grooves of the scroll compressor according to the first embodiment; FIG. It is a block diagram containing the refrigerant circuit of the air conditioner which concerns on 2nd Embodiment. FIG. 11 is an explanatory diagram showing a movement trajectory of an opening of an oil supply passage of an orbiting scroll in a scroll compressor according to a first modified example; FIG. 11 is an explanatory diagram showing a movement trajectory of an opening of an oil supply passage of an orbiting scroll in a scroll compressor according to a second modified example;

<<First embodiment>>
<Structure of scroll compressor>
FIG. 1 is a longitudinal sectional view of a scroll compressor 100 according to the first embodiment.
The scroll compressor 100 is a device that compresses gaseous refrigerant. As shown in FIG. 1 , the scroll compressor 100 includes a closed container 1, a compression mechanism section 2, a crankshaft 3 (shaft), an electric motor 4, a main bearing 5, and an orbiting bearing 6. . The scroll compressor 100 also includes an Oldham ring 7, a balance weight 8, a sub-frame 9, a power terminal 10, and a leg 11, in addition to the components described above.

The sealed container 1 is a shell-shaped container that houses the compression mechanism 2, the crankshaft 3, the electric motor 4, etc., and is substantially sealed. Lubricating oil for lubricating the compression mechanism 2 and each bearing is enclosed in the sealed container 1, and is stored in the bottom of the sealed container 1 as an oil reservoir E1. The sealed container 1 includes a cylindrical cylindrical chamber 1a, a lid chamber 1b that closes the upper side of the cylindrical chamber 1a, and a bottom chamber 1c that closes the lower side of the cylindrical chamber 1a.

A suction pipe P1 is inserted into and fixed to the lid chamber 1b of the sealed container 1. As shown in FIG. The suction pipe P<b>1 is a pipe that guides the refrigerant to the suction port J<b>1 of the compression mechanism section 2 . A discharge pipe P2 is inserted into and fixed to the cylindrical chamber 1a of the sealed container 1. As shown in FIG. The discharge pipe P<b>2 is a pipe that guides the refrigerant compressed by the compression mechanism 2 to the outside of the scroll compressor 100 .

The compression mechanism 2 is a mechanism that compresses gaseous refrigerant as the crankshaft 3 rotates. The compression mechanism section 2 includes a fixed scroll 21 , an orbiting scroll 22 and a frame 23 , and is arranged in the upper space inside the sealed container 1 .

The fixed scroll 21 is a member that forms the compression chamber S1 together with the orbiting scroll 22 . The fixed scroll 21 is installed above the frame 23 and fixed to the frame 23 with bolts B1. As shown in FIG. 1, the fixed scroll 21 includes a base plate 21a and a fixed wrap 21b.

The base plate 21a is a thick member having a circular shape in plan view. The base plate 21a is provided with a suction port J1 through which the refrigerant is introduced via the suction pipe P1. In addition, a region S2 recessed upward is provided in the lower portion near the center of the base plate 21a. The fixing wrap 21b has a spiral shape (see also FIG. 4) and extends downward from the base plate 21a in the region S2 described above. Further, the lower surface of the base plate 21a (the lower surface of the portion outside the region S2) and the tip of the fixing wrap 21b are substantially flush with each other.

The lower surface of the base plate 21a is referred to as the end plate surface 21f of the fixed scroll 21 (see also FIG. 4). The end plate surface 21f is provided with an oil groove G1 (see also FIG. 4) to which lubricating oil is supplied. Details of the oil groove G1 will be described later.

The orbiting scroll 22 is a member that forms a compression chamber S1 between itself and 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 an end plate 22a, an orbiting wrap 22b, and a boss portion 22c. The end plate 22a is a portion that slides between the end plate surface 21f of the fixed scroll 21 and has a disk shape. The orbiting wrap 22b (see also FIG. 3) is a member that forms the compression chamber S1 together with the fixed wrap 21b, and has a spiral shape. The boss portion 22c is a portion fitted to the eccentric portion 3b of the crankshaft 3 and has a tubular shape. As shown in FIG. 1, the turning wrap 22b extends upward from the end plate 22a. On the other hand, the boss portion 22c extends downward from the end plate 22a.

The spiral fixed wrap 21b and the spiral swirl wrap 22b are meshed to form a compression chamber S1 between the fixed wrap 21b and the swirl wrap 22b. The compression chamber S1 is a space for compressing a gaseous refrigerant, and is formed on the outer line side and the inner line side of the orbiting wrap 22b. A discharge port J2 is provided near the center of the base plate 21a of the fixed scroll 21. As shown in FIG. The discharge port J<b>2 is an opening that guides the refrigerant compressed in the compression chamber S<b>1 to the space S<b>3 above the compression mechanism section 2 .

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

A back pressure chamber S<b>4 is provided between the orbiting scroll 22 and the frame 23 . For example, when the gaseous refrigerant is compressed as the volume of the compression chamber S<b>1 is reduced, a downward force is generated to separate the orbiting scroll 22 from the fixed scroll 21 . Therefore, the orbiting scroll 22 is pushed up toward the fixed scroll 21 by the pressure in the back pressure chamber S4. The pressure in the back pressure chamber S<b>4 is normally 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 does not particularly limit the pressure level of the back pressure chamber S4. The pressure in the back pressure chamber S4 is often a value between the suction pressure and the discharge pressure, but in some cases it may temporarily become substantially equal to the discharge pressure.

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

A crankshaft 3 (shaft) shown in FIG. 1 is a shaft that rotates integrally with a rotor 4b of the electric motor 4, and extends vertically. 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 supply piece 3c installed at the lower end of the main shaft portion 3a. The main shaft portion 3a is coaxially fixed to the rotor 4b of the electric motor 4 and rotates integrally with the rotor 4b. The eccentric portion 3b is a portion that rotates eccentrically with respect to the main shaft portion 3a, and is fitted to the boss portion 22c of the orbiting scroll 22 as described above. The orbiting scroll 22 orbits as the eccentric portion 3b rotates while being eccentric.

The oil supply piece 3c is a centrifugal pump that sucks up lubricating oil from the oil reservoir E1 of the sealed container 1, and is installed at the lower end of the main shaft portion 3a. An opening 3h for guiding the lubricating oil is provided at the lower end of the oil supply piece 3c. In addition to the centrifugal force that accompanies the rotation of the oil supply piece 3c, the differential pressure between the upper portion and the lower portion of the oil supply through hole 3d causes the lubricating oil to be sucked up sequentially through the oil supply piece 3c and the oil supply through hole 3d. ing. By providing the oil supply piece 3c (centrifugal pump) near the lower end of the crankshaft 3 (shaft) in this way, the supply of lubricating oil through the oil supply through-hole 3d is facilitated. A predetermined metal piece (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 3 d communicates with the inside of the oil supply piece 3 c and opens at the upper portion of the crankshaft 3 . The oil supply through-hole 3d is branched in a predetermined manner so that the lubricating oil is also supplied to the main bearing 5, the orbiting bearing 6, and the like.

The electric motor 4 is a drive source that rotates the crankshaft 3 and is installed between the frame 23 and the subframe 9 . As shown in FIG. 1, the electric motor 4 includes a stator 4a and a rotor 4b. The stator 4a is fixed to the inner peripheral wall of the cylindrical chamber 1a. The rotor 4b is rotatably arranged radially inside the stator 4a. A crankshaft 3 is fixed to the rotor 4b so as to be coaxial with its central axis (not shown).

The main bearing 5 rotatably supports the upper portion of the main shaft portion 3 a with respect to the frame 23 , and is installed on the peripheral wall surface of the insertion hole H 1 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 installed on the inner peripheral surface of the boss portion 22c.

The Oldham ring 7 is a ring-shaped member that receives the eccentric rotation of the eccentric portion 3b and causes the orbiting scroll 22 to orbit without rotating on its axis. The Oldham ring 7 is mounted in a groove (not shown) on the lower surface of the orbiting scroll 22 and also mounted in 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 installed on the main shaft portion 3a of the crankshaft 3 above the rotor 4b. A separate balance weight (not shown) may be installed on the rotor 4 b of the electric motor 4 .

The subframe 9 is a member that rotatably supports the lower portion of the main shaft portion 3a. As shown in FIG. 1 , the subframe 9 is fixed to the closed container 1 while being arranged below the electric motor 4 . The sub-frame 9 is provided with a hole (not shown) through which the crankshaft 3 is inserted. A sub-bearing 9 a is installed 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 portion 3a with respect to the sub-frame 9. As shown in FIG.
The power terminal 10 is a terminal for supplying electric power to the electric motor 4 and is electrically connected to the electric motor 4 via wiring. A plurality of legs 11 support the closed container 1 and are installed in the bottom chamber 1c.

When the electric motor 4 drives the crankshaft 3 to rotate, the orbiting scroll 22 orbits accordingly. As a result, the successively formed compression chambers S1 are contracted to compress the gaseous refrigerant. The compressed refrigerant is discharged into the space S3 above the compression mechanism portion 2 through the discharge port J2 of the fixed scroll 21 . The refrigerant discharged into the space S3 in this manner is guided to the motor chamber S5 via a flow path (not shown) between the compression mechanism 2 and the closed container 1, and then to the outside via the discharge pipe P2. is discharged to

Further, the lubricating oil stored as an oil reservoir E1 at the bottom of the sealed container 1 rises from the oil supply piece 3c of the crankshaft 3 through the oil supply through hole 3d and reaches the auxiliary bearing 9a, the main bearing 5, the orbiting bearing 6, and the like. lubricate the The lubricating oil that has reached the upper end opening (reference numeral not shown) of the oil supply through-hole 3d is guided to the oil supply channel 12 (see also FIG. 2) of the orbiting scroll 22, which will be described below.

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 the oil supply passage 12 . The oil supply passage 12 is a passage that guides the lubricating oil from the oil supply through hole 3d of the crankshaft 3 (see FIG. 1) to the end plate surface 21f side of the fixed scroll 21 (see FIG. 1). The oil supply channel 12 includes a channel H3, a communication hole H2, and an oil supply hole H4.

As shown in FIG. 2, the end plate 22a is provided with a communication hole H2 in the horizontal direction (direction parallel to the upper and lower surfaces of the end plate 22a). The communication hole H2 is formed, for example, by performing a predetermined cutting process radially inward from the peripheral wall surface of the end plate 22a. The end portion of the communication hole H2 on the outer peripheral side is sealed with a sealing plug N1. As shown in FIG. 2, the upstream side (diameter inner side) of the communication hole H2 communicates with the radially inner space of the boss portion 22c via a relatively short flow path H3 in the vertical direction. Further, the downstream side (diameter direction outer side) of the communication hole H2 communicates with the vertical oil supply hole H4. High-pressure lubricating oil supplied through the oil supply through-hole 3d (see FIG. 1) of the crankshaft 3 is supplied to the fixed scroll 21 through the passage H3, the communication hole H2, and the oil supply hole H4 in sequence. It is designed to be guided to a groove G1 (see FIG. 4).

FIG. 3 is a perspective view of the orbiting scroll 22 provided in the scroll compressor.
As described above, the orbiting scroll 22 includes a disc-shaped end plate 22a, a spiral orbiting wrap 22b, and a tubular boss portion 22c (see FIG. 2). A sealing plug N1 is fitted in the peripheral wall of the end plate 22a of the orbiting scroll 22 to close the end of the communication hole H2 on the outer peripheral side. An opening J4 for an oil supply hole H4 (see FIG. 2) is provided on the upper surface of the end plate 22a. As the orbiting scroll 22 orbits, the opening J4 of the oil supply hole H4 (see FIG. 2) moves to a predetermined extent.

As described above, the pressure in the back pressure chamber S<b>4 (see FIG. 1 ) acts to push up the orbiting scroll 22 toward the fixed scroll 21 . However, if the thrust load between the fixed scroll 21 and the orbiting scroll 22 becomes too large under operating conditions with a high compression ratio, for example, there is a possibility that friction loss increases or seizure occurs on their sliding surfaces. Therefore, in the first embodiment, an arc-shaped oil groove G1 (see FIG. 4) is provided outside the fixed wrap 21b (see FIG. 4) on the end plate surface 21f (see FIG. 4) of the fixed scroll 21, and this oil groove High-pressure lubricating oil is led to G1. Thereby, the thrust load between the fixed scroll 21 and the orbiting scroll 22 can be moderately suppressed.

FIG. 4 is a bottom view of the fixed scroll 21 included in the scroll compressor.
As described above, the fixed scroll 21 has a structure in which the spiral fixed wrap 21b is provided on the base plate 21a. As shown in FIG. 4, the end plate surface 21f of the fixed scroll 21 is provided with an oil groove G1. The oil groove G1 is a groove to 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 oil groove G1 includes an arc-shaped circumferential groove G1a and an oil drain groove G1b connected to one end of the circumferential groove G1a.
The circumferential groove G1a is a groove to which high-pressure lubricating oil is intermittently supplied, and includes an arc portion G11a and a communicating portion G12a. The arc portion G11a is an arc-shaped groove provided on the end plate surface 21f of the fixed scroll 21. As shown in FIG. The circular arc portion G11a is formed, for example, with a center angle of 30° or more and 350° or less with reference to the vicinity of the center (the center of the arc) when the fixed scroll 21 is viewed from below.

Also, at least a portion of the arc portion G11a may overlap a predetermined unbalanced load region. Here, the unbalanced load region is defined as a force (resultant force of centrifugal force and gas load) acting on the end plate surface 21f of the fixed scroll 21 to tilt the orbiting scroll 22 (see FIG. 1). is a region where the end plate 22a (see FIG. 1) of the fixed scroll 21 hits the end plate surface 21f of the fixed scroll 21 particularly strongly. In the present embodiment, a force acts to separate the orbiting scroll 22 from the fixed scroll 21 by intermittently supplying high-pressure lubricating oil to the oil groove G1 including the arc portion G11a. As a result, the thrust load between the orbiting scroll 22 and the fixed scroll 21 is moderately reduced, so that friction loss and seizure on their sliding surfaces can be suppressed.

The communicating portion G12a is a portion that intermittently communicates with the oil supply passage 12 (see FIG. 2), and is connected to the opposite side of the arc portion G11a to the oil drain groove G1b. The communicating portion G12a is formed so as to partially include the movement locus M4 (see FIG. 6) of the opening J4 (see FIGS. 2 and 6) on the end plate surface 21f side of the oil supply passage 12 (see FIG. 2). . As the orbiting scroll 22 (see FIG. 1) moves, the communicating portion G12a of the circumferential groove G1a intermittently communicates with the oil supply passage 12 (see FIG. 2), and high-pressure lubricating oil approximately equal to the discharge pressure is supplied. is guided to the circumferential groove G1a. 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 G12a, or may be different from the groove width of the communication portion G12a. good.

The oil drain groove G1b shown in FIG. 4 is a groove provided radially outward from the end of the circular arc portion G11a (the side opposite to the communicating portion G12a), and communicates with the back pressure chamber S4 (see FIG. 1). . In this embodiment, regardless of the position of the orbiting scroll 22, the oil drain groove G1b always communicates with the back pressure chamber S4 (see FIG. 1).

FIG. 5 is a cross-sectional view of the fixed scroll 21 and orbiting scroll 22 near the oil drain groove G1b.
Note that FIG. 5 shows a partial longitudinal section of the fixed scroll 21 and the orbiting scroll 22 cut along a plane including the oil drain groove G1b. As shown in FIG. 5, the depth L2 of the oil drain groove G1b is shallower than the depth L1 of the circumferential groove G1a. The flow area of the oil drain groove G1b is smaller than the flow area of the circumferential groove G1a. The "flow path area" of the oil drain groove G1b is the cross-sectional area of the flow path of the oil drain groove G1b cut along a plane (not shown) perpendicular to the extending direction of the oil drain groove G1b. (The same applies to the flow path area of the circumferential groove G1a). Further, the groove width of the oil drain groove G1b and the groove width of the circumferential groove G1a may be equal, but are not limited to this. As shown in FIG. 5, the end plate surface of the orbiting scroll 22 corresponding to the circumferential groove G1a and the oil drain groove G1b is planar.

A depth L1 of the circumferential groove G1a shown in FIG. 5 may be, for example, within a range of 1 [mm] or more and 3 [mm] or less. Further, the depth of the oil drain groove G1b may be, for example, within a range of 0.1 [mm] or more and less than 1 [mm]. The difference between the depth of the circumferential groove G1a and the depth of the oil drain groove G1b may be, for example, 0.5 [mm] or more, but is not limited to this.

By making the oil drain groove G1b shallower than the circumferential groove G1a in this way, the flow path resistance of the oil drain groove G1b is increased. Therefore, the high-pressure lubricating oil supplied to the circumferential groove G1a through the oil supply passage 12 (see FIG. 2) flows into the relatively low-pressure back pressure chamber S4 (see FIG. 1) through the oil drain groove G1b. Sudden outflow can be suppressed. As a result, the pressure of the lubricating oil in the circumferential groove G1a is easily maintained at a level close to the discharge pressure. Further, even if foreign matter such as abrasion powder due to friction between the fixed scroll 21 and the orbiting scroll 22 enters the circumferential groove G1a, the foreign matter can be discharged through the oil drain groove G1b.

FIG. 6 is an explanatory view showing a locus M4 of movement of the opening J4 of the oil supply passage by partially enlarging the region K1 of FIG.
In FIG. 6, the movement locus M4 of the 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 dashed line. As described above, high-pressure lubricating oil is intermittently supplied to the circumferential groove G1a from the oil supply through hole 3d (see FIG. 1) of the crankshaft 3 via the oil supply passage 12 (see FIG. 2). In the example of FIG. 6, as the orbiting scroll 22 (see FIG. 2) rotates, the opening J4 of the oil supply passage 12 (see FIG. 2) returns to its original position through the circular movement locus M4. , the oil supply passage 12 and the circumferential groove G1a communicate with each other twice. Further, the communication portion G12a of the circumferential groove G1a is formed so as to partially include the movement locus M4 of the opening J4 of the oil supply passage 12 (see FIG. 2). A sufficient amount of high-pressure lubricating oil is intermittently supplied to the circumferential groove G1a by appropriately adjusting the length of the communicating portion G12a at the design stage.

FIG. 7A is an explanatory diagram of a state in which the opening J4 of the oil supply passage of the orbiting scroll does not communicate with the circumferential groove G1a of the fixed scroll 21. FIG.
In FIG. 7A, the annular sliding surface V1 between the fixed scroll 21 and the orbiting scroll 22 (see FIG. 3) is indicated by dots. 7A shows the position of the opening J4 by projecting the opening J4 of the oil supply passage 12 (see FIG. 2) of the orbiting scroll 22 onto the fixed scroll 21. FIG. In the state of FIG. 7A, the opening J4 has not yet communicated with the circumferential groove G1a while the orbiting scroll 22 is moving. By providing such a non-communicating section, it is possible to prevent a large amount of lubricating oil from being wastefully supplied to the circumferential groove G1a. Therefore, it is possible to prevent a large amount of lubricating oil from flowing into the compression chamber S1 (see FIG. 1) from the circumferential groove G1a, thereby suppressing the heating loss of the refrigerant. That is, it is possible to prevent the amount of refrigerant in the compression chamber S1 from decreasing (decreasing the refrigerating capacity) due to the expansion associated with the temperature rise of the refrigerant. After the state shown in FIG. 7A, the position of the opening J4 changes in the order of FIGS. 7B and 7C.

FIG. 7B is an explanatory diagram of a state in which the opening J4 of the oil supply passage of the orbiting scroll communicates with the circumferential groove G1a of the fixed scroll 21. FIG.
As shown in FIG. 7B, the opening J4 of the oil supply passage 12 (see FIG. 2) of the orbiting scroll 22 communicates with the circumferential groove G1a, so that high-pressure lubricating oil approximately equal to the discharge pressure is supplied to the circumferential groove G1a. be done. Thereby, the thrust load between the fixed scroll 21 and the orbiting scroll 22 can be reduced. In addition, through a small gap between the end plate surface 21f (see FIG. 4) of the fixed scroll 21 and the end plate 22a (see FIG. 1) of the orbiting scroll 22, the pressure is compressed from the circumferential groove G1a to the compression chamber S1 (see FIG. 1). is properly lubricated. As a result, the stationary wrap 21b (see FIG. 1), the orbiting wrap 22b (see FIG. 1), and the like are lubricated, so that wear and seizure can be suppressed. Further, since the lubricating oil is also supplied to the back pressure chamber S4 (see FIG. 1) through the oil drain groove G1b, each sliding portion of the back pressure chamber S4 is sufficiently lubricated.

Further, since the lubricating oil is supplied from the circumferential groove G1a to the relatively low-pressure compression chamber S1 (see FIG. 1), the pressure at the upper portion of the oil feed through hole 3d in the crankshaft 3 (see FIG. 1) It becomes lower than the pressure (discharge pressure) of the lower part of 3 d of through-holes. That is, a differential pressure is generated between the upper portion and the lower portion of the crankshaft 3 . Due to such a differential pressure, the lubricating oil is sucked up from the oil reservoir E1 (see FIG. 1) through the oil supply through-hole 3d even when the scroll compressor 100 is operated at a low speed. Therefore, it is not particularly necessary to use a gear pump (not shown) such as a trochoid pump, and it is sufficient to provide a simply-configured oil supply piece 3c (centrifugal pump: see FIG. 1), which reduces the manufacturing cost of the scroll compressor 100. can.

As shown in FIG. 7B, the radial outer end of the oil drain groove G1b protrudes outside the sliding surface V1 (area indicated by dots) between the fixed scroll 21 and the orbiting scroll 22. As shown in FIG. That is, the oil drain groove G1b is always in communication with the back pressure chamber S4 (see FIG. 1) (also see FIGS. 7A and 7C). Here, since the oil drain groove G1b is shallower than the circumferential groove G1a (the passage area is smaller), a predetermined pressure loss occurs in the oil drain groove G1b. As a result, even if the oil drain groove G1b is always in communication with the back pressure chamber S4 (see FIG. 1), the pressure in the circumferential groove G1a is likely to be maintained higher than that in the back pressure chamber S4. Therefore, the thrust load between the fixed scroll 21 and the orbiting scroll 22 can be moderately reduced.

FIG. 7C is an explanatory diagram of a state in which the opening J4 of the oil supply passage of the orbiting scroll does not communicate with the circumferential groove G1a of the fixed scroll 21. FIG.
As shown in FIG. 7C, lubricating oil is not particularly supplied to the oil groove G1 when the opening J4 of the oil supply passage 12 (see FIG. 2) is out of the circumferential groove G1a. In this state, the high-pressure lubricating oil existing in the circumferential groove G1a gradually flows out to the back pressure chamber S4 (see FIG. 1) through the oil drain groove G1b. As described above, since the oil drain groove G1b is shallower than the circumferential groove G1a, it is possible to prevent the lubricating oil present in the circumferential groove G1a from suddenly flowing out through the oil drain groove G1b.

FIG. 8 is a time chart showing the communication state of the oil grooves.
In FIG. 8, the horizontal axis indicates time, and the vertical axis indicates the communication state of the oil groove G1 (see FIG. 4). The vertical axis in FIG. 8 indicates the state of communication of the oil groove G1, as indicated by the dashed line in FIG. (See FIG. 1) and the oil drain groove G1b (See FIG. 4) are in communication (chain line in FIG. 8). bottom of the time chart).

As indicated by the solid line in FIG. 8, the circumferential groove G1a (see FIG. 4) and the oil supply passage 12 (see FIG. 2) are alternately connected and disconnected temporally. In the example of FIG. 8, the circumferential groove G1a and the oil supply passage 12 are out of communication from time t0 to t1 (state shown in FIG. 7A), and from time t1 to t2 thereafter, the circumferential groove G1a and the oil supply passage 12 are not in communication. are in communication (state in FIG. 7B), and return to non-communication between times t2 and t3 (state in FIG. 7C). In this manner, the circumferential groove G1a and the oil supply passage 12 intermittently communicate with each other. 8, the oil drain groove G1b (see FIG. 4) always communicates with the back pressure chamber S4 (see FIG. 1).

The opening J4 of the oil supply passage 12 (see FIG. 2) communicates with the circumferential groove G1a twice while making one round of the circular movement locus M4 (see FIG. 6). Illustration of communication is omitted.

<effect>
According to the first embodiment, high-pressure lubricating oil is intermittently supplied to the arc-shaped circumferential grooves G1a (see FIG. 4) provided in the end plate surface 21f of the fixed scroll 21 . In addition, since the oil drain groove G1b is shallower (has a narrower passage area) than the circumferential groove G1a, the lubricating oil in the circumferential groove G1a is easily maintained at a high pressure. This prevents the end plate 22a of the orbiting scroll 22 from strongly hitting the fixed scroll 21 in the vicinity of the circumferential groove G1a, thereby suppressing friction loss and seizure on the sliding surface. In addition, since lubricating oil is appropriately supplied to each sliding portion of the compression chamber S1 and the back pressure chamber S4, the reliability of the scroll compressor 100 is enhanced.

Further, the circumferential groove G1a of the fixed scroll 21 intermittently communicates with the opening J4 of the oil supply passage 12, so that a differential pressure is generated between the upper portion and the lower portion of the oil supply through hole 3d of the crankshaft 3. As a result, even when the scroll compressor 100 is operating at a low speed, the lubricating oil is sucked up through the oil supply through-hole 3d (see FIG. 1), so that insufficient lubrication can be suppressed. Further, since a centrifugal pump can be used as the oil supply piece 3c (see FIG. 1), the manufacturing cost of the scroll compressor 100 can be reduced.

Further, according to the first embodiment, since the oil drain groove G1b (see FIG. 4) communicates with the back pressure chamber S4 (see FIG. 1), foreign matter such as abrasion powder is discharged into the circumferential groove G1a (see FIG. 4). ), the foreign matter is discharged through the oil drain groove G1b. Therefore, clogging of the circumferential groove G1a with foreign matter can be suppressed, and the effect of supplying oil to each sliding portion via the circumferential groove G1a can be maintained for a long period of time.

In conventional scroll compressors, lubricating oil is supplied to the back pressure chamber S4 and the compression chamber S1 through a minute gap between the end plate surface 21f of the fixed scroll 21 and the end plate 22a of the orbiting scroll 22. Therefore, it was difficult to fine-tune the amount of oil supplied. For example, fluctuations in the amount of oil supplied per unit time were likely to occur due to the operating conditions of the scroll compressor and the effects of variations in accuracy of parts. On the other hand, in the first embodiment, if the groove width and depth of the oil drain groove G1b (see FIG. 4) are adjusted at the design stage of the scroll compressor 100, the amount of oil supplied increases or decreases accordingly. It becomes easy to adjust the amount of oil to be supplied.

Further, since the pressure in the back pressure chamber S4 is often higher than that in the compression chamber S1, conventional scroll compressors tend to supply insufficient amount of oil to the back pressure chamber S4. For example, when an attempt is made to increase the amount of oil supplied to the back pressure chamber S4, the amount of oil supplied to the compression chamber S1 is excessively increased, resulting in refrigerant heating loss and a decrease in refrigerating capacity. In contrast, in the first embodiment, since the oil groove G1 is always in communication with the exhaust pressure chamber S4, the amount of oil supplied to the back pressure chamber S4 is increased without particularly increasing the amount of oil supplied to the compression chamber S1. be able to. This promotes lubrication of each sliding portion of the back pressure chamber S4.

<<Second embodiment>>
In the second embodiment, an air conditioner W1 (refrigeration cycle device: see FIG. 9) including the scroll compressor 100 (see FIG. 1) described in the first embodiment will be described.

FIG. 9 is a configuration diagram including the refrigerant circuit Q1 of the air conditioner W1 according to the second embodiment.
In addition, solid line arrows in FIG. 9 indicate the flow of the refrigerant during the heating operation.
On the other hand, dashed arrows in FIG. 9 indicate the flow of the refrigerant during the cooling operation.
The air conditioner W1 is a device that performs air conditioning such as cooling and heating. As shown in FIG. 9, 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, an indoor fan 76 and .

In the example of FIG. 9, 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. Also, the indoor heat exchanger 75 and the indoor fan 76 are provided in the indoor unit U2.

The scroll compressor 100 is a device that compresses 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 its heat transfer tubes (not shown) 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 is provided with an outdoor fan motor 72 a as a drive source and is installed near the outdoor heat exchanger 71 .

The indoor heat exchanger 75 is a heat exchanger in which heat is exchanged between the refrigerant flowing through the heat transfer tube (not shown) and the indoor air (air-conditioned room air) sent from the indoor fan 76 . be. The indoor fan 76 is a fan that sends indoor air to the indoor heat exchanger 75 . The indoor fan 76 is provided with an indoor fan motor 76 a as a drive source and is installed near the indoor heat exchanger 75 .

The expansion valve 73 is a valve that reduces the pressure of the refrigerant condensed in 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 cooling operation (see the dashed arrow in FIG. 9), in the refrigerant circuit Q1, the scroll compressor 100, the outdoor heat exchanger 71 (condenser), the expansion valve 73, and the indoor heat exchanger 75 (evaporator ) in sequence, the refrigerant circulates. On the other hand, during heating operation (see the solid line arrow in FIG. 9), in the refrigerant circuit Q1, the scroll compressor 100, the indoor heat exchanger 75 (condenser), the expansion valve 73, and the outdoor heat exchanger 71 (evaporator ) in sequence, the refrigerant circulates.

<effect>
According to the second embodiment, the air conditioner W1 includes the scroll compressor 100 with low manufacturing cost and high performance and reliability. As a result, the manufacturing cost of the air conditioner W1 as a whole can be reduced, and its performance and reliability can be improved.

<<Modification>>
Although the scroll compressor 100 and the air conditioner W1 according to the present invention have been described above in each embodiment, the present invention is not limited to these descriptions, and various modifications can be made. For example, the scroll compressor may be configured as shown in FIG. 10 (first modification) or FIG. 11 (second modification).

FIG. 10 is an explanatory diagram showing a movement locus M4 of the opening J4 of the oil supply passage of the orbiting scroll in the scroll compressor according to the first modification.
A region K2 shown in FIG. 10 corresponds to the region K1 shown in FIG. 4 (first embodiment). As shown in FIG. 10, the circumferential groove GA1a includes an arc portion G11a and a communicating portion G13a. The communicating portion G13a is formed so as to include a part of the movement locus M4 of the opening J4 of the oil supply passage 12 (see FIG. 2). As shown in FIG. 10, the opening J4 and the oil groove G1 may communicate with each other once while the opening J4 goes around the circular movement locus M4. Even with such a configuration, high-pressure lubricating oil can be appropriately supplied to the circumferential groove GA1a by appropriately adjusting the length of the communicating portion G13a at the design stage.

FIG. 11 is an explanatory diagram showing a movement locus M4 of the opening J4 of the oil supply passage of the orbiting scroll in the scroll compressor according to the second modification.
As shown in FIG. 11, in the circumferential groove GB1a, the end opposite to the oil drain groove G1b (see FIG. 4) may be formed in a T shape. Even with such a configuration, high-pressure lubricating oil can be appropriately supplied to the circumferential groove GB1a by appropriately adjusting the length of the communication portion G14a at the design stage. Further, in the example of FIG. 11, the opening J4 and the oil groove G1 are separated by 1 by the time the opening J4 of the oil supply passage 12 (see FIG. 2) goes around the circular movement locus M4 and returns to the original position. Although a configuration in which the connection is made twice is shown, the connection may be made twice. Even with such a configuration, the same effects as those of the first embodiment can be obtained.

Further, in each embodiment, the case where the circumferential groove G1a is arcuate has been described, but it may be in a predetermined shape different from the arcuate shape.
Further, in each embodiment, an example in which the oil drain groove G1b (see FIG. 4) is provided radially outward from the end of the circumferential groove G1a (see FIG. 4) has been described, but the oil drain groove G1b is located in the back pressure chamber. As long as it communicates with S4 (see FIG. 1), the direction in which the oil drain groove G1b extends can be changed as appropriate.

Also, in each embodiment, the case where the oil drain groove G1b (see FIG. 4) is formed shallower than the circumferential groove G1a (see FIG. 4) has been described, but the present invention is not limited to this. For example, the groove width of the oil drainage groove G1b is formed narrower than the groove width of the circumferential groove G1a so that the flow area of the oil drainage groove G1b is smaller than the flow area of the circumferential groove G1a. good too. In this case, the depth of the oil drain groove G1b and the depth of the circumferential groove G1a may be equal or different.

Also, the air conditioner W1 (see FIG. 9) described in the second embodiment can be applied to various types of air conditioners such as room air conditioners, package air conditioners, and multi air conditioners for buildings. Moreover, although 2nd Embodiment demonstrated the air conditioner W1 (refrigeration cycle apparatus) provided with the scroll compressor 100, it does not restrict to this. For example, the second embodiment can be applied to other "refrigerating cycle devices" such as refrigerators, water heaters, air-conditioning water heaters, chillers, and refrigerators.

Moreover, although each embodiment demonstrated the case where the refrigerant|coolant was compressed with the scroll compressor 100, it does not restrict to this. That is, each embodiment can also be applied when a predetermined gas other than refrigerant is compressed by the scroll compressor 100 .

Moreover, each embodiment is described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to those having all the described configurations. Moreover, it is possible to appropriately add, delete, or replace a part of the configuration of each embodiment with another configuration.
Further, the mechanisms and configurations described above show those considered necessary for explanation, and do not necessarily show all the mechanisms and configurations on the product.

REFERENCE SIGNS LIST 1 airtight container 2 compression mechanism 12 oil supply passage 21 fixed scroll 21b fixed wrap 21f end plate surface 22 orbiting scroll 22b orbiting wrap 23 frame 3 crankshaft (shaft)
3c Lubrication piece (centrifugal pump)
3d Oil supply through-hole 4 Electric motor 4a Stator 4b Rotor 71 Outdoor heat exchanger 73 Expansion valve 75 Indoor heat exchanger 100 Scroll compressor G1 Oil grooves G1a, GA1a, GB1a Circumferential grooves G11a Circular parts G12a, G13a, G14a Communicating parts G1b Drainage groove H1 Insertion hole J4 Opening L1 Depth (depth of circumferential groove)
L2 depth (depth of oil drain groove)
M4 movement trajectory S1 compression chamber S4 back pressure chamber W1 air conditioner (refrigeration cycle device)

Claims (4)

a closed container;
an electric motor having a stator and a rotor and housed in the closed container;
a shaft having an oil supply through-hole through which lubricating oil flows and rotating integrally with the rotor;
a stationary scroll having a spiral stationary wrap;
an orbiting scroll having a spiral orbiting wrap and having a compression chamber formed between the fixed wrap and the orbiting wrap;
a frame that has an insertion hole for the shaft and supports 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 passage for guiding lubricating oil from the oil supply through hole to the end plate surface side of the fixed scroll,
The end plate surface of the fixed scroll is provided with an arc-shaped circumferential groove and an oil drain groove connected to one end of the circumferential groove,
The oil drain groove communicates with the back pressure chamber,
The flow passage area of the oil drain groove is smaller than the flow passage area of the circumferential groove,
the oil supply passage and the circumferential groove are intermittently communicated ,
The circumferential groove has an arc portion having an arc shape and a communicating portion that intermittently communicates with the oil supply passage,
The communication portion is connected to the arc portion on the side opposite to the oil drain groove, and is formed so as to partially include the movement locus of the opening of the oil supply passage on the end plate surface side,
A scroll compressor , wherein the oil supply passage alternately communicates with the communication portion and the arc portion included in one of the circumferential grooves . The depth of the circumferential groove is in the range of 1 mm or more and 3 mm or less,
The scroll compressor according to claim 1, wherein the depth of the oil drain groove is within a range of 0.1 mm or more and less than 1 mm. A centrifugal pump provided near the lower end of the shaft,
The scroll compressor according to claim 1, wherein the oil supply through-hole opens at an upper portion of the shaft. A refrigeration cycle apparatus comprising the scroll compressor according to any one of claims 1 to 3 , an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger.

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