JP2006207544A - Scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scroll compressor capable of improving separability of lubricant in an oil separation chamber with a simple structure and securing a well lubricated state. <P>SOLUTION: The scroll compressor is equipped with an oil separating means for separating a portion of the lubricant from a compressed working fluid. The oil separating means includes: the oil separating chamber 90 provided in a discharge passage of the working fluid extending from a scroll unit 40 to a discharge port and has a inflow port and an outflow port for the working fluid; an oil separating pipe 94 provided in the oil separation chamber 90 and which has one end opening to the oil separation chamber 90 and another end connected to the outflow port; and a separation flow passage which is partitioned between the inner peripheral face of the oil separation chamber 90 and the outer peripheral face of the oil separation pipe 94, extending from the inflow port to the one end of the oil separation pipe 94, for making the working fluid which flows into the oil separation chamber 90 to flow in a spiral around the oil separation pipe 94 and centrifuging the lubricant from the working fluid. The separation flow passage has a throttle 96 between the upstream end and the downstream end where a flow cross section area is throttled. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a scroll compressor.

  This type of scroll compressor is applied to, for example, a refrigeration circuit of a vehicle air conditioner, and a scroll unit including fixed and movable scrolls is accommodated in the housing. A space between one inner end wall of the housing and the scroll unit is defined as a drive chamber, and a revolving unit for revolving the movable scroll with respect to the fixed scroll is accommodated in the drive chamber. Along with the operation of the swivel unit, the scroll unit performs a series of processes of sucking, compressing and discharging the working fluid by the swivel movement of the movable scroll. On the other hand, a discharge chamber is defined between the other inner end wall of the housing and the scroll unit, and high-pressure working fluid is discharged from the scroll unit into the discharge chamber. The working fluid is introduced into the scroll unit through the suction port of the housing, and the high-pressure working fluid in the discharge chamber is delivered from the discharge chamber through the discharge port of the housing.

By the way, in general, the refrigerant as the working fluid includes lubricating oil for the bearing of the swivel unit and the like, but when the lubricating oil circulates in the refrigeration circuit, its refrigerating capacity is lowered. Therefore, in this type of scroll compressor, an oil separation chamber that partially separates the lubricating oil from the compressed working fluid, and an oil that communicates with the oil separation chamber via the communication hole and temporarily stores the separated lubricating oil. A chamber adjacent to the discharge chamber. The oil chamber and the drive chamber are connected by a recirculation path for lubricating oil, and only the lubricating oil is supplied from the oil chamber to the drive chamber, that is, the swivel unit through this recirculation path (see, for example, Patent Document 1).
JP 11-82352 A

In the conventional compressor described above, it is preferable that the lubricating oil separating ability in the oil separating chamber is higher.
The present invention has been made on the basis of the above-described circumstances, and the object of the present invention is to improve the separation capability of the lubricating oil in the oil separation chamber with a simple configuration and to ensure a good lubrication state. Is to provide a machine.

  In order to achieve the above-described object, according to the present invention, a housing having a suction port and a discharge port, and suction of a working fluid disposed in the housing and including lubricating oil introduced from the suction port, A scroll unit that executes a series of processes including compression and discharge steps, and sends a high-pressure working fluid through the discharge port; and oil separation means that partially separates the lubricating oil from the working fluid discharged by the scroll unit; The oil separation means is provided in a discharge path of the working fluid from the scroll unit to the discharge port, and has an oil separation chamber having an inlet and an outlet of the working fluid; Provided in the oil separation chamber, having one end opened to the oil separation chamber and the other end connected to the outlet The operation separated from the inlet to one end of the oil separation pipe between the oil separation pipe, an inner peripheral surface of the oil separation chamber and an outer peripheral surface of the oil separation pipe, and flows into the oil separation chamber A separation flow path for causing the fluid to spirally flow around the oil separation pipe and centrifuging the lubricating oil from the working fluid, the separation flow path between the upstream end and the downstream end There is provided a scroll compressor characterized in that it has a restriction with a reduced flow path cross-sectional area (Claim 1).

  According to the scroll compressor of the present invention, since the cross-sectional area of the flow path is reduced in the restriction of the separation flow path, the working fluid including the lubricating oil is accelerated when flowing through the restriction. The acceleration of the working fluid results in an increase in the centrifugal force used for the centrifugal separation, that is, the centrifugal force applied to the working fluid and the lubricating oil flowing in a spiral shape. Therefore, in the throttle, the lubricating oil is easily centrifuged from the working fluid, and as a result, the ability to separate the lubricating oil in the oil separation chamber is improved.

  As a preferred aspect, the throttle is provided at the downstream end of the separation channel (Claim 2). The amount of lubricating oil contained in the working fluid decreases as the working fluid approaches the downstream end of the separation flow path as the lubricating oil is centrifuged. For this reason, the amount of lubricating oil contained in the working fluid is small at the downstream end, and centrifugal separation of the lubricating oil from the working fluid becomes difficult. However, in this case, the working fluid is accelerated by the throttle provided at the downstream end to increase the centrifugal force, and the lubricating oil is centrifuged from the working fluid even at the downstream end. The separation ability of the is further improved.

  As a preferred aspect, at least one of the inner peripheral surface of the oil separation tube and the outer peripheral surface of the oil separation tube is formed from the upstream end to the downstream end of the separation flow path in order to obtain the throttle. A tapered surface is included (claim 3). In this case, the lubricating oil that is separated from the working fluid in the separation channel and adheres to the inner peripheral surface of the oil separation tube and the outer peripheral surface of the oil separation tube flows smoothly along the tapered surface, from the oil separation chamber. It is discharged promptly.

As described above, in the scroll compressor according to the first to third aspects, since the separation performance of the lubricating oil in the oil separation chamber is improved by providing a restriction in the separation flow path of the oil separation chamber, it is returned to the drive chamber. A sufficient amount of lubricating oil is ensured, and the lubricating state is kept good. For this reason, these scroll compressors have a long life while having a simple configuration, and further reduce power loss.
In particular, according to the scroll compressor of claim 2, by providing a throttle at the downstream end of the separation flow path, the ability to separate the lubricating oil is further improved.

  In the scroll compressor according to the third aspect, since the lubricating oil separated from the oil separation chamber is quickly discharged, the lubricating oil returned to the driving chamber is reliably ensured.

FIG. 1 shows a scroll compressor of one embodiment applied to a refrigeration circuit of a vehicle air conditioner.
The scroll compressor is disposed in the circulation flow path 2 of the refrigeration circuit through which the refrigerant circulates, and the condenser 4, the receiver 6, the expansion valve 8 and the evaporation are disposed downstream of the compressor in the circulation flow path 2 in the circulation direction of the refrigerant. Containers 10 are sequentially arranged. The compressor compresses the refrigerant as the working fluid and sends it to the condenser 4, whereby the refrigerant circulates in the circulation channel 2. The refrigerant contains lubricating oil, and the lubricating oil in the refrigerant not only lubricates the bearings and various sliding surfaces in the compressor, but also functions to seal the sliding surfaces.

  The scroll compressor includes a housing 12, and the housing 12 includes a drive casing 14 and a compression casing 16. The drive and compression casings 14 and 16 are connected to each other by a plurality of connection bolts 18. As will be described later, this compressor is installed in the engine room of the vehicle so that the lubricating oil is stored in the bottom of the compression casing 16 and the vertical direction of FIG. .

  A drive shaft 20 is disposed in the drive casing 14, and the drive shaft 20 has a large-diameter end portion 22 on the compression casing 16 side, and a small-diameter shaft portion 24 extends from the large-diameter end portion 22. The large diameter end portion 22 is rotatably supported by the drive casing 14 via a needle bearing 26, and the small diameter shaft portion 24 is rotatably supported by the drive casing 14 via a ball bearing 28. Further, a lip seal 30 is attached to the small diameter shaft portion 24 between the ball bearing 28 and the large diameter end portion 22, and the lip seal 30 is slidably contacted with the small diameter shaft portion 24 so that the inside of the drive casing 14 is hermetically sealed. It is divided into.

  The small diameter shaft portion 24 of the drive shaft 20 protrudes from the drive casing 14, and the driven side of the electromagnetic clutch 32 is attached to the protruding end. The electromagnetic clutch 32 has a drive pulley 34 on its drive side, and the drive pulley 34 is rotatably supported by the drive casing 14 via a bearing 36. The drive pulley 34 is rotated by receiving power from the engine 38 of the vehicle, and the rotation of the drive pulley 34 can be intermittently transmitted to the drive shaft 20 via the electromagnetic clutch 32. Therefore, if the electromagnetic clutch 32 is turned on while the engine 38 is being driven, the drive shaft 20 is rotated together with the drive pulley 34.

On the other hand, although not shown, the compression casing 16 is formed with a suction port and a discharge port on its outer peripheral wall, and the suction port and the discharge port are connected to the evaporator 10 or the condenser 4 of the refrigeration circuit by the circulation flow path 2. Is done.
A scroll unit 40 is accommodated in the compression casing 16, and a drive chamber 42 is formed between the scroll unit 40 and the inner end wall of the drive casing 14, and between the scroll unit 40 and the outer peripheral wall of the compression casing 16. A suction chamber 44 communicating with the suction port of the compression casing 16 is formed therebetween. The drive chamber 42 and the suction chamber 44 are in communication with each other.

The scroll unit 40 includes a movable scroll 46 and a fixed scroll 48, and each of the movable and fixed scrolls 46 and 48 is formed of a substrate 50 and a spiral wall 52 formed integrally with the substrate 50.
As is clear from FIG. 1, the movable and fixed scrolls 46 and 48 are arranged such that the substrates 50 face each other and the spiral walls 52 mesh with each other. In this arrangement, the front end surface of each spiral wall 52 is in sliding contact with the other substrate 50, and the spiral walls 52 are in local contact with each other, thereby compressing between the movable scroll 46 and the fixed scroll 48. A chamber 54 is formed. The refrigerant suction process and the refrigerant compression / discharge process into the compression chamber 54 are executed as the movable scroll 46 turns.

  In order to impart a turning motion to the movable scroll 46 described above, a turning unit is disposed in the drive chamber 42. More specifically, the movable scroll 46 and the large-diameter end 22 of the drive shaft 20 are connected to each other via a needle bearing 56, an eccentric bush 58 and a crank pin 60, and the movable scroll 46 and the drive casing 14 are connected to each other. A ball-type orbiting thrust bearing 62 for preventing the rotation of the movable scroll 46 is disposed. Reference numeral 64 in FIG. 1 indicates a counterweight, and this counterweight 64 is attached to an eccentric bush 58.

On the other hand, the fixed scroll 48 is fixed in the compression casing 16 via a plurality of fixing bolts (not shown), and between the fixed scroll 48 and the end wall 16 a of the compression casing 16, a discharge chamber 66 and an oil chamber 68. Are partitioned vertically via a partition wall 70.
The oil chamber 68 communicates with the drive chamber 42 through an oil recirculation means, that is, an orifice filter 74 provided in the through hole 72 of the fixed scroll 48. The orifice filter 74 has a cylindrical shape surrounding the proximal end portion of the orifice tube 76 on the oil chamber 68 side, the orifice tube 76, a sleeve 78 partially fitted to the orifice tube 76 from the outside, and being fused to the sleeve 78. And a filter material 80. The orifice tube 76 is obtained, for example, by extending a metal hollow cylinder in the axial direction thereof, and an extremely small internal passage (not shown) for lubricating oil passes through the inside of the orifice tube 76, and an oil chamber 68 and a drive chamber. 42 communicates with the filter material 80 and the internal flow path of the orifice tube 76.

On the other hand, the discharge chamber 66 communicates with the upstream compression chamber 54 via the discharge valve 82, and the discharge valve 82 has a discharge hole 84 as a valve hole provided in the fixed scroll 48 and a lead that opens and closes the discharge hole 84. The valve body 86 has a stopper plate 88 that regulates the opening degree of the reed valve body 86.
An oil separation chamber 90 is defined in the discharge chamber 66. More specifically, as shown in an enlarged view in FIG. 2, the discharge chamber 66 and the oil separation chamber 90 are partitioned by a cylindrical partition wall (hereinafter referred to as a peripheral wall 92). The partition wall 70 extends in the vertical direction along the end wall 16 a from the outer peripheral wall of the compression casing 16. An oil separation pipe 94 is concentrically disposed in the peripheral wall 92, and the oil separation pipe 94 is fitted to the inner peripheral surface of the peripheral wall 92 by press-fitting, and a partition wall from the large diameter cylindrical part 94a. A small-diameter cylindrical portion 94b extending downwardly toward 70. The oil separation chamber 90 is formed inside the region of the peripheral wall 92 extending from the large-diameter cylindrical portion 94a of the oil separation pipe 94 to the partition wall 70. In this compressor, the inner peripheral surface of the peripheral wall 92 in the region. However, it is formed as a tapered surface 92a that decreases in diameter as it goes from the large-diameter cylindrical portion 94a toward the partition wall 70. For this reason, the distance between the outer peripheral surface of the small diameter cylindrical portion 94b of the oil separation pipe 94 and the inner peripheral surface of the peripheral wall 92 is reduced from the upper end to the lower end of the small diameter cylindrical portion 94b, and at the lower end of the small diameter cylindrical portion 94b. It is the minimum. Accordingly, a diaphragm 96 is formed between the lower end of the small diameter cylindrical portion 94b and the tapered surface 92a. The peripheral wall 92 is integrally formed when the compression casing 16 is formed by, for example, aluminum die casting, and the tapered surface 92a is made of cast skin.

  The oil separation pipe 94 is prevented from coming off from the peripheral wall 92 by a retaining ring 98, and the upper end of the peripheral wall 92 is closed by the plug 100, but the inner periphery of the peripheral wall 92 is between the plug 100 and the oil separation pipe 94. A horizontal hole 102 connected to the discharge port is opened on the surface. In other words, the oil separation chamber 90 communicates with the downstream discharge port through the oil separation pipe 94, and the upper end of the small diameter cylindrical portion 94b forms an outlet of the oil separation chamber 90 on the inside thereof.

  The oil separation chamber 90 and the discharge chamber 66 upstream thereof communicate with each other via two introduction holes 104 provided on the peripheral wall 92 side by side. These introduction holes 104 are positioned in the vicinity of the upper end of the small-diameter cylindrical portion 94b of the oil separation pipe 94 when viewed in the vertical direction, open to the tapered surface 92a of the peripheral wall 92 at the upper part of the oil separation chamber 90, and flow in the oil separation chamber 90 It has an open end that forms an inlet. Further, these introduction holes 104 penetrate the peripheral wall 92 in the tangential direction, and the opening end of the introduction hole 104 on the oil separation chamber 90 side is not the front surface of the small diameter cylinder part 94b of the oil separation pipe 94 but the small diameter cylinder part 94b. An opening is provided so as to face between the side and the inner peripheral surface of the peripheral wall 92.

  Further, the oil separation chamber 90 and the oil chamber 68 communicate with the oil chamber 68 through a communication hole 106 formed in the partition wall 70 as a bottom wall of the oil separation chamber 90. More specifically, the communication hole 106 has an opening end that penetrates the partition wall 70 in the vertical direction and opens at the upper surface and the lower surface of the partition wall 70. The tapered surface 92a of the peripheral wall 92 rises continuously from the opening end of the communication hole 106 on the oil separation chamber 90 side.

According to the scroll compressor described above, the movable scroll 46 orbits as the drive shaft 20 rotates. At this time, the rotation of the movable scroll 46 is blocked by the orbiting thrust bearing 62. The orbiting movement of the movable scroll 46 periodically moves the compression chamber 54 in the direction of moving toward and away from the discharge hole 84, and accordingly, the volume of the compression chamber 54 is increased or decreased.
As a result, the refrigerant is sucked into the compression chamber 54 from the suction chamber 44, and the sucked refrigerant is compressed in the process in which the compression chamber 54 moves toward the discharge hole 84 and its volume decreases. . When the compression chamber 54 reaches the discharge hole 84, the pressure of the refrigerant in the compression chamber 54 overcomes the shutoff pressure of the discharge valve 82 and opens the discharge valve 82, and the compressed refrigerant is discharged from the compression chamber 54 through the discharge hole 84. 66 is discharged.

Then, the compressed refrigerant flows from the discharge chamber 66 into the oil separation chamber 90 through the introduction hole 104 and flows downward while turning around the small diameter cylindrical portion 94b of the oil separation pipe 94. At this time, the mist-like lubricating oil contained in the refrigerant is centrifuged and adheres to the inner surface of the peripheral wall 92, and the separated lubricating oil descends due to its own weight and flows into the oil chamber 68 through the communication hole 106.
The compressed refrigerant from which the lubricating oil is thus separated flows into the oil separation pipe 94 from the lower end of the oil separation pipe 94 and rises, and is supplied to the condenser 4 through the discharge port.

  On the other hand, the lubricant stored in the oil chamber 68 is recirculated into the drive chamber 42 through the orifice filter 74 using the pressure difference between the drive chamber 42 and the oil chamber 68, and the needle bearing 56 constituting the swivel unit. Are supplied to each sliding part. That is, the lubricating oil filtered by passing through the filter material 80 is supplied to the drive chamber 42 through the orifice tube 76.

  Here, in the compressor described above, the working fluid is caused to flow spirally between the outer peripheral surface of the small diameter cylindrical portion 94b of the oil separation pipe 94 and the inner peripheral surface of the peripheral wall 92, and the lubricating oil is centrifuged from the working fluid. A separation channel is defined, and a restriction 96 is formed in the separation channel. Since the restriction 96 restricts the cross-sectional area of the separation passage, the working fluid containing the lubricating oil is accelerated when flowing through the restriction 96. The acceleration of the working fluid results in an increase in the centrifugal force used for the centrifugal separation, that is, the centrifugal force applied to the working fluid and the lubricating oil flowing in a spiral shape. For this reason, in the throttle 96, the lubricating oil is easily centrifuged from the working fluid, and as a result, the capability of separating the lubricating oil in the oil separation chamber 90 is improved.

And the refrigerating circuit of the vehicle air conditioner provided with the compressor mentioned above has a good refrigerating capacity because the amount of lubricating oil flowing through the circulation channel 2 is small.
The present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, in one embodiment, the throttle 96 is provided at the downstream end of the separation flow path, but any flow area between the upstream end and the downstream end of the separation flow path, that is, the small diameter cylindrical portion of the oil separation pipe 94. What is necessary is just to provide between the upper end of 94b, and a lower end. However, as in one embodiment, the restriction 96 is preferably provided at the downstream end of the separation channel. The reason is as follows. The amount of lubricating oil contained in the working fluid decreases as the working fluid approaches the downstream end of the separation flow path as the lubricating oil is centrifuged. For this reason, the amount of lubricating oil contained in the working fluid is small at the downstream end of the separation flow path, making it difficult to centrifuge the lubricating oil from the working fluid. However, when the throttle 96 is provided at the downstream end of the separation flow path, even if the amount of lubricating oil contained in the working fluid is small, the working fluid is accelerated by the throttle 96 so that the lubricating oil is further centrifuged from the working fluid. In addition, the ability to separate the lubricating oil in the oil separation chamber is further improved.

  In one embodiment, the channel cross-sectional area of the separation channel continuously decreases toward the throttle 96, but the channel cross-sectional area may be reduced discontinuously by the throttle. That is, the diaphragm may be formed by providing a step on the inner peripheral surface of the peripheral wall 92. However, in order to smoothly lower the lubricating oil adhering to the inner peripheral surface of the peripheral wall 92, it is preferable to continuously reduce the flow path cross-sectional area by the tapered surface 92a as in the embodiment.

  Furthermore, in one embodiment, the outer diameter of the separation flow path is reduced by using the oil separation pipe 94 having a straight tubular small-diameter cylindrical portion 94b and forming the tapered surface 92a on the inner peripheral surface of the peripheral wall 92. Although the throttle 96 is formed, as shown in FIG. 3, the oil separation pipe 108 having a small-diameter cylindrical portion 108b whose outer diameter is increased from the upper end toward the lower end in the peripheral wall 92 having a constant inner diameter. And the restriction 96 may be formed in the separation channel by expanding the inner diameter of the separation channel. Also in this case, when the lubricating oil adheres to the outer peripheral surface of the small-diameter cylindrical portion 108b of the oil separation pipe 108 for some reason, the outer peripheral surface of the small-diameter cylindrical portion 108b is formed as a tapered surface in order to smoothly lower the lubricating oil. Is preferred. However, as in one embodiment, the restriction 96 is preferably formed by reducing the outer diameter of the separation channel. The reason is as follows. Since the turning radius of the working fluid in the separation channel is defined by the outer diameter of the separation channel, the turning radius of the working fluid in the separation channel can be obtained by reducing the outer diameter of the separation channel to form the throttle 96. Is reduced by the diaphragm 96. When the turning radius of the working fluid is reduced at the throttle 96, the centrifugal force applied to the working fluid and the lubricating oil increases, and the lubricating oil is more easily separated from the working fluid.

  Furthermore, in one Example, although the taper surface 92a of the surrounding wall 92 was formed with the casting skin, you may form with processing skins, such as cutting. However, it is preferable that the taper surface 92a is formed by casting skin. This is because the casting skin has an appropriate surface roughness and the lubricating oil easily adheres, so that the separating ability of the lubricating oil is improved.

It is a longitudinal cross-sectional view of the scroll compressor of one Example applied to the refrigerating circuit of the vehicle air conditioner. FIG. 2 is an enlarged view of the vicinity of an oil separation chamber in FIG. 1. It is an enlarged view of the oil separation chamber vicinity of a modification.

Explanation of symbols

12 housing 16 compression casing 40 scroll unit 46 movable scroll 48 fixed scroll 54 compression chamber 82 discharge valve 90 oil separation chamber 92 peripheral wall 92a taper surface 94 oil separation tube 94a large diameter cylindrical portion 94b small diameter cylindrical portion 96 throttle

Claims (3)

A housing having a suction port and a discharge port;
A series of processes including suction, compression, and discharge processes are performed on the working fluid including the lubricating oil that is disposed in the housing and introduced from the suction port, and a high-pressure working fluid is sent through the discharge port. A scroll unit;
Oil separation means for partially separating the lubricating oil from the working fluid discharged by the scroll unit;
In a scroll compressor comprising:
The oil separating means includes
An oil separation chamber provided in a discharge path of the working fluid from the scroll unit to the discharge port, and having an inlet and an outlet of the working fluid;
An oil separation pipe provided in the oil separation chamber and having one end opened to the oil separation chamber and the other end connected to the outlet;
The oil separation chamber is partitioned between the inner peripheral surface of the oil separation chamber and the outer peripheral surface of the oil separation pipe from the inflow port to one end of the oil separation pipe, and the working fluid flowing into the oil separation chamber is separated into the oil. A separation flow path for spirally flowing around the tube to centrifuge the lubricating oil from the working fluid;
The scroll compressor characterized in that the separation flow path has a throttle with a flow path cross-sectional area narrowed between an upstream end and a downstream end.   The scroll compressor according to claim 1, wherein the throttle is provided at the downstream end of the separation channel.   At least one of the inner peripheral surface of the oil separation tube and the outer peripheral surface of the oil separation tube includes a tapered surface formed from the upstream end to the downstream end of the separation flow path in order to obtain the throttle. The scroll compressor according to claim 1 or 2.

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