JP2010007550A - Scroll fluid machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scroll fluid machine improved in compression efficiency by optimizing the back pressure of a movable scroll to effectively prevent the movable scroll from being overturned while securing the reliability of a scroll unit. <P>SOLUTION: This scroll fluid machine 1 includes a high-pressure chamber 48 which receives high pressure generated by the discharge pressure of lubricating oil for lubricating the scroll unit 14 at the center of the rear surface 26b of the end plate 26 of the movable scroll 22 and a seal ring 52 which forms a back pressure chamber 50 reduced in pressure than the high-pressure chamber by partitioning itself and the high-pressure chamber at the outer periphery of the rear surface of end plate of the movable scroll. The seal ring includes a partly swelled section 58 at a position corresponding to the outermost peripheral side predetermined range of an outer peripheral side compression chamber 36a formed at the outer peripheral side of the lap 30 of the movable scroll in a plan view. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a scroll type fluid machine, and more particularly, to a scroll type fluid machine suitable for being incorporated in a refrigeration air conditioner or a heat pump type water heater.

  In this type of scroll type fluid machine, for example, a hermetic scroll compressor is composed of an asymmetric fixed scroll and a movable scroll each having a pair of spiral wraps on each end plate, and movable with respect to the fixed scroll. As the scroll revolves, a compression chamber for the working fluid is formed between the laps. The compression chamber is provided with a scroll unit that moves toward the center of the end plate while reducing its volume.

Then, a suction chamber in which the working fluid suction pressure acts on the end plate of the fixed scroll, and a high pressure at which the discharge pressure of the working fluid acts on the central portion of the rear surface of the end plate of the movable scroll by the lubricating oil that lubricates the scroll unit. A high pressure chamber, and an annular seal portion that forms a back pressure chamber that is decompressed from the high pressure chamber on the outer peripheral portion of the back surface of the movable scroll by partitioning the high pressure chamber. There has been disclosed a technique of suppressing the overturning of the movable scroll by providing a recessed portion that communicates with the back pressure of the movable scroll relatively higher than the pressure of the suction chamber (see, for example, Patent Document 1).
International Publication No. 2005/038254 Pamphlet

However, in the above prior art, a groove as a recess is formed in the seal portion, that is, the sliding surface on which the movable scroll slides on the end plate of the fixed scroll, so that the sliding area of the movable scroll on the end plate of the fixed scroll is reduced. It is not preferable for the smooth operation of the scroll unit.
Further, the working gas in the suction chamber is heated by the lubricating oil and the density thereof is lowered, which may cause a reduction in the compression efficiency of the scroll unit.

  The present invention has been made in view of such problems, and while ensuring the reliability of the scroll unit, the back pressure of the movable scroll is optimized to effectively prevent the movable scroll from overturning, and the compression thereof. An object of the present invention is to provide a scroll type fluid machine capable of improving the efficiency.

  In order to achieve the above object, a scroll type fluid machine according to claim 1 is composed of an asymmetric fixed scroll and a movable scroll in which spiral wraps are paired on each end plate, respectively. On the other hand, the orbiting scroll revolves to form a compression chamber for the working fluid between the laps, and the compression chamber moves toward the center of the end plate while reducing its volume, and the end plate of the orbiting scroll Formed in the center of the back surface of the movable scroll, and is arranged so as to partition the high-pressure chamber from a high-pressure chamber to which a high pressure to which the discharge pressure of the working fluid is applied by the lubricating oil that lubricates the scroll unit. A seal ring that forms a back pressure chamber that is depressurized from the high pressure chamber at the outer periphery of the back surface of the end plate, and the seal ring is a movable scroll in plan view. Tsu a position corresponding to a predetermined range of the outermost circumferential side of the outer peripheral side compression chamber formed on the outer peripheral side of the flop, part of which is characterized by having a 膨成 portion bulging outward.

  According to a second aspect of the present invention, in the first aspect of the present invention, in the first aspect, the bulging portion defines the end of closing of the movable scroll wrap in the vicinity of the suction chamber where the suction pressure of the working fluid acts. In this case, the phase of the revolving orbiting motion of the movable scroll is about 70 ° from this reference point, and the distance between the fixed scroll wrap and the movable scroll wrap is maximized.

  Furthermore, the invention according to claim 3 is characterized in that, in claim 2, the bulging portion is formed by a plurality of arc portions each having a predetermined radius of curvature smoothly and continuously.

  According to the scroll type fluid machine of the first aspect of the present invention, the seal ring corresponds to a predetermined range on the outermost peripheral side of the outer peripheral side compression chamber formed on the outer peripheral side of the wrap of the movable scroll in a plan view. In addition, it has a bulging portion that partially bulges outward. Thereby, the high pressure chamber can be enlarged with a simple configuration that only forms the expanded portion, and high pressure pressure can be applied as the back pressure to the outer peripheral side compression chamber, without reducing the sliding area of the movable scroll, In addition, the scroll-type fluid machine effectively prevents the movable scroll from overturning by ensuring the back pressure of the movable scroll while ensuring the reliability of the scroll unit without reducing the compression efficiency of the scroll unit. Can improve the compression efficiency.

  According to the second aspect of the present invention, when the end of the movable scroll wrap in the vicinity of the suction chamber is used as a reference point for the orbiting orbiting of the movable scroll, the bulging portion is moved from the reference point to the movable scroll. The phase of the revolving orbiting motion is around 70 °, and the separation distance between the fixed scroll wrap and the movable scroll wrap is maximized. As a result, the expansion portion is formed at a position that substantially matches the outer peripheral compression chamber on the outermost peripheral side of the movable scroll in a plan view. The rollover of the movable scroll in the low compression ratio operation of the fluid machine can be effectively prevented.

  Furthermore, according to the invention described in claim 3, the bulging portion is formed in the outer peripheral side compression chamber on the outermost peripheral side of the movable scroll by smoothly continuing a plurality of arc portions each having a predetermined radius of curvature. Since the bulging portion can be positioned at the pinpoint, the rollover of the movable scroll can be more effectively prevented.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of a hermetic scroll compressor as an example of a scroll type fluid machine according to the present embodiment. The compressor 1 is incorporated in a refrigeration circuit such as a refrigeration air conditioner or a heat pump type hot water heater. It is. The circuit includes a path through which a carbon dioxide refrigerant (hereinafter referred to as a refrigerant), which is an example of a working fluid, circulates. The compressor 1 sucks the refrigerant from the path, compresses the refrigerant, and discharges the refrigerant toward the path.

  The compressor 1 includes a shell 2. A center shell 4 that forms a cylindrical body of the shell 2 is hermetically fitted with a top shell 6 and a bottom shell 8 on the upper and lower sides thereof, and the inside of the center shell 4 is hermetically sealed. The discharge pressure of the refrigerant is acting. A suction pipe 10 for sucking the refrigerant taken in from the circuit is connected to the refrigerant suction chamber formed in the center shell 4, and the compressed refrigerant in the shell 2 is sent to the circuit at an appropriate position of the top shell 6. A discharge pipe 12 is connected.

In the center shell 4, a scroll unit 14, an electric motor 16, and a pump unit 18 are accommodated in this order from above, and a rotating shaft 20 is disposed in the electric motor 16, and the rotating shaft 20 is energized by energization of the electric motor 16. Driven by rotation.
The rotary shaft 20 has an upper end connected to the scroll unit 14 and a lower end connected to the pump unit 18, and the rotary shaft 20 is driven to rotate by the electric motor 16, whereby the scroll unit 14 sucks and compresses the refrigerant. And a series of discharge processes.

  Specifically, the scroll unit 14 includes an asymmetric movable scroll 22 and a fixed scroll 24, and the movable scroll 22 includes a mirror plate 26, and a spiral that extends toward the mirror plate 28 of the fixed scroll 24 on the mirror plate surface 26 a of the mirror plate 26. On the other hand, a spiral wrap 32 extending toward the end plate 26 is also set up on the end plate surface 28 a of the end plate 28 of the fixed scroll 24.

The wraps 30 and 32 are formed on the basis of a predetermined involute curve, and are arranged in pairs to cooperate with each other, so that the refrigerant from the refrigerant suction chamber 34 to which the suction pipe 10 is connected at the end plate 28. To form a compression chamber 36 between the wraps 30 and 32.
The suction chamber 34 is formed on the end plate 28 of the fixed scroll 24 so as to face the end plate surface 26 a, and the suction pressure Ps of the refrigerant acts on the suction chamber 34, while the compression chamber 36 is caused by the revolving orbiting motion of the movable scroll 22 relative to the fixed scroll 24. Then, it moves toward the center of the end plates 28, 40 while reducing its volume.

In order to give the orbiting scroll 22 a revolving orbiting motion, a boss 38 is formed on the back surface 26b side of the end plate 26, and the boss 38 is rotatable to an eccentric shaft 40 integrally formed on the upper end side of the rotary shaft 20 via a bearing. It is supported by. The rotation of the movable scroll 22 is blocked by a rotation blocking pin (not shown).
On the other hand, the fixed scroll 24 is supported and fixed to a main frame 42 fixed to the inside of the center shell 4, and a discharge hole 44 that can communicate with the compression chamber 36 is formed in the central portion of the fixed scroll 24. ing.

On the other hand, the pump unit 18 sucks the lubricating oil stored inside the bottom shell 8, and the sucked lubricating oil passes through an oil passage 46 drilled in the rotating shaft 20 from the upper end of the rotating shaft 20. And is supplied to the scroll unit 14 and the like, and contributes to the lubrication of each sliding portion and bearing, and the sealing and lubrication of the sliding surface.
Specifically, the lubricating oil that is heated and discharged by the refrigerant discharge pressure flows down from the upper end of the rotating shaft 20 toward the electric motor 16 along the rotating shaft 20 through the oil passage 46, while the movable scroll 22 A high pressure chamber 48 for lubricating oil is formed by being supplied to the central portion of the back surface 26b of the end plate 26.

  Between the back surface 26b and the main frame 42, there is disposed a seal ring 52 that partitions the space between the high pressure chamber 48 and forms a back pressure chamber 50 that is decompressed more than the high pressure chamber 48 on the outer periphery of the back surface 26b. . The lubricating oil supplied from the high pressure chamber 48 to the back pressure chamber 50 across the seal ring 52 slides with respect to the fixed scroll 24 after passing through the gap 54 between the outer peripheral surface 26 c of the end plate 26 and the main frame 42. It is supplied to a sliding surface 56 formed on the end plate 26 of the movable scroll 22.

  According to the compressor 1 described above, the orbiting scroll 22 revolves without rotating along with the rotation of the rotating shaft 20, so that the refrigerant sucked into the scroll unit 14 via the suction pipe 10 is compressed into the compression chamber 36. The refrigerant in the compression chamber 36 is compressed while being moved toward the center of the scroll unit 14 and then discharged into the shell 2 from the discharge hole 44 and circulates in the shell 2 and then passes through the discharge pipe 12. It is sent out of the compressor 1.

By the way, the seal ring 52 of this embodiment is not a complete annular shape, but has a deformed shape having a bulging portion 58 that is swelled by being partially enlarged in plan view.
Specifically, referring to the plan view of the scroll unit 14 as viewed from the AA direction in FIG. 1 in FIG. 2, the expanding portion 58 is a movable scroll at the closing end of the inner circumferential side compression chamber 36 b near the suction chamber 34. When the reference point P of the orbiting revolution 22 is the reference point P, the phase of the orbiting revolution centering around the revolution center C of the movable scroll 22 from the reference point P is about 70 °, and the lap 32 and the movable scroll of the fixed scroll 24 are moved. 22 is formed at a position where the distance between the wrap 30 and the wrap 30 is maximum, and this position is the outermost peripheral side of the movable scroll 22 in a plan view in the compression chamber 36 formed along with the revolving orbiting motion of the movable scroll 22. It corresponds so that it may correspond to the position of the outer peripheral side compression chamber 36a located in this.

  As shown in the cross-sectional view of the main part of the scroll unit 14 as viewed from the B-B direction in FIG. 3, the seal ring 52 is formed when the seal ring 52 is annular due to the expanded portion 58 (expanded). The area of the high pressure chamber 48 in the back pressure chamber 50 is expanded to the outer peripheral side of the movable scroll 22 as compared with the position overlapping the portion 58), and the thrust load Fs by the outer peripheral compression chamber 36a is increased by the expanding portion 58, And the back pressure Fb of the movable scroll 22 by the high-pressure chamber 48 is supported.

  As described above, in the present embodiment, the high-pressure chamber 48 can be enlarged with a simple configuration that only forms the expanded portion 58 in the seal ring 52, and a high-pressure pressure can be applied to the outer peripheral side compression chamber 36a as a back pressure. Therefore, the back pressure of the movable scroll 22 is ensured while ensuring the reliability of the scroll unit 14 without reducing the area of the sliding surface 56 of the movable scroll 22 and without reducing the compression efficiency of the scroll unit 14. It is possible to effectively prevent the movable scroll 22 from overturning and to improve the compression efficiency of the compressor 1.

In particular, since the bulging portion 58 is formed at a position that substantially matches the outer peripheral compression chamber 36a on the outermost peripheral side of the movable scroll 22 in plan view, the compression ratio between the compression chamber 36 and the back pressure chamber 50 decreases. The overturning of the movable scroll 22 in the low compression ratio operation of the compressor 1 can be effectively prevented.
The description of one embodiment of the present invention is finished above, but the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above embodiment, as shown in FIG. 2, the seal ring 52 is partially enlarged in plan view and has a bulging portion 58 that swells without constriction. For example, a plurality of circular arc portions each having a predetermined radius of curvature may smoothly be formed, for example, a constricted protrusion shape or an oval shape. In this case, since the bulging portion 58 can be positioned at the outer peripheral side compression chamber 36a on the outermost peripheral side of the movable scroll 22 at a pinpoint, the overturning of the movable scroll 22 can be further effectively prevented, which is preferable. .

  Moreover, although the said embodiment demonstrated the compressor 1 of the enclosed scroll using the carbon dioxide refrigerant incorporated in refrigeration circuits, such as a refrigerating air conditioner and a heat pump type hot water heater, this invention is not limited to this and various The present invention can be applied to fluid machines such as compressors and expanders in various fields using the above working fluids.

1 is a longitudinal sectional view showing a hermetic scroll compressor according to an embodiment of the present invention. It is a top view of the scroll unit seen from the AA direction of FIG. It is principal part sectional drawing of the scroll unit seen from the BB direction of FIG.

Explanation of symbols

1 Hermetic scroll compressor (scroll type fluid machine)
DESCRIPTION OF SYMBOLS 14 Scroll unit 22 Movable scroll 24 Fixed scroll 26 End plate 26b Back surface 28 End plate 30 Wrap 32 Wrap 34 Suction chamber 36 Compression chamber 36a Outer peripheral side compression chamber 36b Inner peripheral side compression chamber 48 High pressure chamber 50 Back pressure chamber 52 Seal ring 58 Expansion part

Claims (3)

Each end plate is composed of an asymmetric fixed scroll and a movable scroll, each of which has a pair of spiral wraps standing upright. The movable scroll revolves with respect to the fixed scroll, and operates between the wraps. A scroll unit that forms a fluid compression chamber and moves while reducing the volume of the compression chamber toward the center of the end plate;
A high-pressure chamber formed at the center of the back surface of the end plate of the movable scroll, to which a high pressure is applied to which a working fluid discharge pressure is applied by a lubricating oil that lubricates the scroll unit;
A seal ring that is disposed so as to partition the high-pressure chamber, and that forms a back-pressure chamber that is depressurized from the high-pressure chamber at an outer peripheral portion of the rear surface of the end plate of the movable scroll;
The seal ring is a bulging portion partially bulging outward at a position corresponding to a predetermined range on the outermost circumferential side of the outer circumferential compression chamber formed on the outer circumferential side of the wrap of the movable scroll in plan view. A scroll type fluid machine comprising:   When the end of the wrap of the movable scroll in the vicinity of the suction chamber where the suction pressure of the working fluid acts is used as a reference point for the revolving orbiting motion of the movable scroll, the bulging portion starts from the reference point. 2. The scroll according to claim 1, wherein a phase of the revolving orbiting motion is approximately 70 °, and the separation distance between the wrap of the fixed scroll and the wrap of the movable scroll is maximized. Type fluid machine.   The scroll fluid machine according to claim 2, wherein the bulging portion includes a plurality of circular arc portions each having a predetermined radius of curvature smoothly and continuously.

Images