KR101751345B1 - Scroll compressor with split type orbitting scroll - Google Patents

Abstract

The present invention relates to a scroll compressor having a separable orbiting scroll. According to an aspect of the present invention, there is provided a scroll compressor including a case; A fixed scroll installed in the case; A lap portion engaging with the fixed scroll to form a compression chamber; A base portion disposed on a bottom surface of the wrap portion; Engaging means for movably coupling the wrap portion to the fixed scroll side with respect to the base portion; A driving motor coupled to a back surface of the base portion to eccentrically rotate the base portion and the wrap portion; And a main frame supporting the base portion and installed in the case.

Description

[0001] SCROLL COMPRESSOR WITH SPLIT TYPE ORBITTING SCROLL [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor having a separable orbiting scroll, and more particularly, to a scroll compressor in which compression is performed while orbiting scroll is rotated with respect to a fixed scroll.

Generally, a scroll compressor is a compressor that compresses a refrigerant gas by changing a volume of a compression chamber formed by a pair of opposing scrolls. The scroll compressor is more efficient than a reciprocating compressor or a rotary compressor, has low vibration and noise, can be made compact and lightweight, and is widely used particularly in air conditioners.

The scroll compressor may be divided into a low-pressure type and a high-pressure type according to the type of refrigerant supplied to the compression chamber. That is, in the low-pressure scroll compressor, the refrigerant is indirectly sucked into the compression chamber through the inner space of the casing, and the inner space of the casing is divided into the suction space and the discharge space. On the other hand, in the high-pressure scroll compressor, the refrigerant is directly supplied to the compression chamber without passing through the inner space of the casing, and is discharged to the inner space of the casing, so that the entire inner space of the casing is formed as the discharge space.

The scroll compressor may be divided into a tip chamber type and a back pressure type by a sealing method of a compression chamber. That is, in the tip chamber type, a tip chamber is provided at the tip of the lap of each scroll, so that the tip chamber of the compressor rises while the compressor is in operation, and is brought into close contact with the end plate of the opposite scroll. On the other hand, in the back pressure system, a back pressure chamber is formed on the back surface of one scroll, and oil or refrigerant of intermediate pressure is introduced into the back pressure chamber so that the scroll is pressed against the pressure of the back pressure chamber, Typically, the tip chamber method is applied to a low pressure scroll compressor while the back pressure method is applied to a high pressure scroll compressor.

On the other hand, the rotary shaft of the drive motor is coupled to one side of the orbiting scroll, and the other side of the orbiting scroll is engaged with the fixed scroll. Particularly, in the case of orbiting scroll, since both side surfaces rotate in contact with the fixed scroll and the main frame, it is necessary to precisely shape the shape in order to suppress the vibration and minimize the loss due to friction. For this purpose, the orbiting scroll is formed by machining the bearing surface to be in contact with the main frame and then machining the lap portion. However, there is a possibility that the bearing surface is damaged in the process of machining the lap portion. In addition, since the shape of the orbiting scroll and the fixed scroll, especially the shape and size of the wrap portion, must be different depending on the capacity of the compressor, a considerable time is required for designing and manufacturing the orbiting scroll.

The pressure applied to the back pressure chamber by the bearing surface of the orbiting scroll varies depending on the pressure applied to the back pressure chamber. In order to prevent the leakage of the refrigerant, the pressure applied to the back pressure chamber is properly maintained do. However, in the conventional scroll compressor, since the entire orbiting scroll must be supported by the pressure of the back pressure chamber, a considerable high pressure must be applied to the back pressure chamber, and if there is a variation in the back pressure chamber pressure, There is a problem that greatly affects the performance of the system. Particularly, the pressure in the back pressure chamber is influenced by the discharge pressure. Since the discharge pressure varies depending on the load applied to the compressor, the sealing performance between the orbiting scroll and the fixed scroll and the friction loss are affected by the load fluctuation There was a problem.

It is a technical object of the present invention to provide a scroll compressor capable of achieving sufficient sealing performance while minimizing friction loss between orbiting scroll and fixed scroll even in the presence of load fluctuations.

According to an aspect of the present invention, A fixed scroll installed in the case; A lap portion engaging with the fixed scroll to form a compression chamber; A base portion disposed on a bottom surface of the wrap portion; Engaging means for movably coupling the wrap portion to the fixed scroll side with respect to the base portion; A driving motor coupled to a back surface of the base portion to eccentrically rotate the base portion and the wrap portion; And a main frame supporting the base portion and installed in the case.

In the above aspect of the present invention, the orbiting scroll which is conventionally formed integrally is separated into the lap portion and the base portion, and the lap portion and the base portion can be separately manufactured. This makes it possible to share the base portion in a plurality of compressors having different capacities, thereby making it easier to manufacture the orbiting scroll. In addition, since the lap portion is fixed to the fixed scroll side with respect to the base portion, only the lap portion can be separated and moved through the back pressure. As a result, since excessive back pressure is not required, the friction loss due to the back pressure can be reduced, and the intermediate pressure, which is less fluctuating relative to the discharge pressure, can be used, and stable performance can be obtained.

Here, the coupling means may include a key that is fitted to the lap portion and the base portion, respectively, and may include a pin coupled to the lap portion and the base portion, respectively. This allows the lap portion and the base portion to engage without excessive pressure or clamping force.

When a key is used as the coupling means, the key may be configured as a separate member separated from the lap portion or the base portion, and may be press-fitted and fixed to either side of the lap portion or the base portion. In addition, the key may be formed integrally with either the lap portion or the base portion.

A back pressure chamber communicating with the compression chamber may be formed between the lap portion and the base portion. The back pressure chamber is formed between the lap portion and the base portion and is separated from another space inside the compressor. The upper surface is defined by the lap portion, and the lower surface is defined by the base portion. The pressure of the back pressure chamber is applied to the lap portion and the base portion, respectively. However, since the base portion is supported by the main frame, only the lap portion is moved to the fixed scroll side by the back pressure of the back pressure chamber.

The back pressure chamber may include a sealing means for sealing the back pressure chamber between the lap portion and the base portion, and an O-ring may be used as the sealing means.

A back pressure hole communicating the back pressure chamber and the compression chamber may be formed through the wrap portion. Accordingly, since the length of the back pressure hole can be shortened, the loss of the back pressure can be minimized, and the back pressure hole can be easily processed.

The back pressure hole may be formed at a position where both the discharge pressure and the intermediate pressure defined as a value between the discharge pressure and the suction pressure may be applied to the back pressure chamber. The pressure applied to the compression chamber continuously varies depending on the operation principle of the scroll compressor. Specifically, at the outermost of the fixed lap and the orbiting lap, the pressure corresponding to the suction pressure gradually increases to have an intermediate pressure, Discharge occurs while reaching the pressure. Further, since the pressure chamber has a shape extending in the circumferential direction similar to the crescent moon, the pressure at a specific position of the orbiting scroll also changes.

Depending on the position, both the intermediate pressure and the discharge pressure can be applied. When the back pressure hole is formed at this position, the intermediate pressure is applied to the back pressure chamber at the beginning, and the discharge pressure is also applied while the orbiting wrap is rotated. Therefore, pressure to be interlocked with the compression chamber is applied to the back pressure chamber. In other words, when the pressure in the compression chamber is low, it is advantageous to reduce the loss due to friction by lowering the discharge pressure because there is less fear of leakage relatively. When the pressure in the compression chamber is high, It is necessary to shut off the leakage. By the above-described configuration, it becomes possible to appropriately adjust the discharge pressure.

Specifically, when the discharge opening time of the orbiting wrap is?, The back pressure hole may be located at a point having a phase angle larger than? And smaller than? + 180 ° on the orbiting wrap.

According to another aspect of the present invention, there is provided a scroll compressor including: a fixed scroll; An orbiting scroll in which the orbiting wrap forming the compression chamber together with the fixed scroll is movably coupled to the fixed scroll side; Engaging means for engaging the orbiting wrap to the orbiting scroll; And pressurizing means for introducing a part of the working fluid of the compression chamber to generate a discharge pressure for moving the orbiting wrap to the fixed scroll side.

According to aspects of the present invention having the above-described structure, the orbiting scroll which is formed integrally as a single body can be divided into two parts, and each of the parts can be separately manufactured. In a plurality of compressors having different capacities, . Making it easier to produce the orbiting scroll. In addition, since a sufficient degree of sealing can be achieved even at a relatively low back pressure, a lower pressure can be used as a back pressure instead of a discharge pressure that varies according to operating conditions such as a load, so that the compressor can be driven more stably do.

1 is a sectional view showing a first embodiment of a scroll compressor according to the present invention.
Fig. 2 is a partial cutaway view showing an enlarged view of the compression mechanism in Fig. 1. Fig.
Fig. 3 is an exploded perspective view showing the orbiting scroll in Fig. 1. Fig.
Fig. 4 is an enlarged cross-sectional view of the orbiting scroll in Fig. 1. Fig.
5A to 5C are plan views schematically showing a process of operating the first embodiment shown in FIG.
FIG. 6 is a graph showing the magnitude of the axial force according to the position of the back pressure hole formed in the orbiting scroll in FIG. 1;
7 is a sectional view showing a modified example of the orbiting scroll.
8 is an exploded perspective view showing still another modification of the orbiting scroll.

Hereinafter, an embodiment of a scroll compressor according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a longitudinal sectional view showing a first embodiment of a scroll compressor according to the present invention, FIG. 2 is a partial cutaway view showing an assembly state of a compression mechanism in the scroll compressor according to FIG. 1, Fig. 3 is an exploded perspective view showing the orbiting scroll in the compressor.

1 to 3, the scroll compressor according to the present invention is characterized in that the inner space of the case 1 is divided into a suction space 11 as a low pressure portion and a discharge space 12 as a high pressure portion, And a main frame 3 is fixedly installed between the suction space 11 and the discharge space 12 of the case 1. The main frame 3 is fixed to the suction space 11 of the case 1, A fixed scroll 4 is fixed to an upper surface of the main frame 3 and is eccentrically coupled to a crankshaft 23 of the driving motor 2 between the main frame 3 and the fixed scroll 4, An orbiting scroll (5) forming a pair of two compression chambers (P) continuously moving together with the fixed scroll (4) is pivotally mounted. An ore ring 6 is provided between the fixed scroll 4 and the orbiting scroll 5 to prevent the orbiting scroll 5 from rotating.

The suction pipe 13 is connected to the suction space 11 of the case 1 while the discharge pipe 14 is connected to the discharge space 12. [

Here, although not shown in the drawing, the casing may be provided with a sealed predetermined discharge space and partitioned by a discharge plenum fixedly coupled to the fixed scroll 4, the suction space being a low pressure part and the discharge space being a high pressure part, The inner space of the case may be partitioned into a suction space and a discharge space by a high-low pressure separation plate (not shown) fixed to the upper surface of the fixed scroll and closely attached to the inner circumferential surface of the case.

The stationary scroll 4 protrudes from the bottom surface of the fixed plate 41 and is formed in an involute shape so as to form a compression chamber P together with the orbiting wrap 52 of the orbiting scroll 5 . A suction port (not shown) is formed on the outer peripheral surface of the fixed plate 4 of the fixed scroll 4 so that the suction space 11 of the case 1 communicates with the compression chamber P, A discharge port 44 is formed at the center of the hard plate portion 41 so that the compression chamber P and the discharge space 12 of the case 1 communicate with each other. In the drawings, reference numeral 7 denotes a sub-frame, 8 denotes a discharge valve, 21 denotes a stator, and 22 denotes a rotor.

Therefore, in the above embodiment, the refrigerant flows from the outside into the suction space 11, which is the low-pressure portion of the case 1, through the suction pipe 13, and the low-pressure refrigerant in the suction space 11 flows into the suction port And is compressed and moved to the center of the orbiting scroll and the fixed scroll by the orbiting scroll 5 and then discharged to the discharge space 12 of the case 1 through the discharge port 44 of the fixed scroll 4 The process of discharging is repeated.

2 and 3, the orbiting scroll 5 is configured to be divided into two parts. Specifically, the orbiting scroll 5 and the lap portion 50, which are engaged with the fixed scroll, (Not shown). The lap portion 50 is configured to include a revolving lap 52 that engages with the fixed lap 42 to form a compression chamber and a lap flange 54 integrally formed with the revolving lap 52. The lap flange 54 has a disk shape, and on both sides of the bottom surface, a key portion 56 for engaging with the base portion 60 is formed.

The base portion 60 is coupled to the lap 50 in a state of being opposed to the bottom surface of the lap flange 54. Specifically, the base portion 60 includes a base flange 64, And a boss portion 68 formed on the bottom surface of the base flange 64 to engage with the crankshaft 23 described above.

A keyhole 66 for fastening with the key-shaped portion 56 is formed at both side edges of the upper surface of the base flange 64. By inserting the key-shaped portion into the keyhole, the lap 50 can move in the axial direction of the crankshaft with respect to the base portion 60, but can not be moved with respect to the radial direction or the circumferential direction of the base portion do. However, since the axial movement of the lap 50 is limited by the distance between the fixed scroll and the main frame 3, the key shape 56 is inserted into the key hole 66 . That is, both of them can be stably combined by simply inserting the key portion into the keyhole without using a method such as bolt fastening or welding.

In addition, the above-mentioned anti-blocking 6 as the above-described anti-rotation mechanism is coupled to the bottom surface of the base portion 60. Specifically, the alum ring 6 includes a ring-shaped portion 6a contacting with the bottom surface of the base flange 64, and two opposite sides of the ring-shaped portion 6a are provided with two First protrusions 6b are formed. The first protrusion 6b is inserted into the first protrusion groove 3a formed in the main frame 3. Two second protrusions 6c are also formed on both sides of the upper surface of the ring-shaped portion 6b with a phase difference of 180 degrees. The second protrusions 6c are inserted into second protrusion grooves 64a formed on the bottom surface of the base flange 64, respectively.

Accordingly, even if the crankshaft 23 transmits rotational force to the base portion 60, the base portion 60 is pivotally moved in a state where the base portion 60 is prevented from being rotated by the otal bearing 6, The lap portion 50 coupled to limit the radial movement of the lap portion 60 is also pivoted together with the base portion 60.

On the other hand, a back pressure chamber 62 is defined at the center of the upper surface of the base flange 64 by a seal 62a. 4, the back pressure chamber 62 is positioned between the bottom surface of the lap flange 54 and the upper surface of the base flange 64, and a seal 62a Pressure space 62 communicates with the internal space of the back pressure chamber 62. The back pressure chamber 62 communicates with the compression chamber 62 through the back pressure chamber 62, Is formed through the flange (64).

Therefore, in the process of sucking and compressing the refrigerant, a part of the compressed refrigerant present in the compression chamber flows into the back pressure chamber through the back pressure hole 54a. Since the internal pressure of the back pressure chamber becomes higher than the pressure around the base flange 64, the base portion 60 is lifted along the axial direction from the lap portion 50, The sealing is performed between the wraps 52.

Here, the pressure in the back pressure chamber may be determined according to the position of the back pressure hole. That is, the pressure inside the back pressure chamber increases as the back pressure hole moves closer to the center of the orbiting wrap (52) of the orbiting scroll, and the pressure inside the back pressure chamber decreases as it moves outward.

5A to 5C are plan views schematically showing a process in which the refrigerant is compressed by the orbiting wrap and the fixed lap. The solid line corresponds to the center line of the fixed lap 42, and the dotted line corresponds to the center line of the orbiting wrap 52 . Fig. 5C corresponds to the case where the pressure in the compression chamber reaches the discharge pressure and discharge starts. As described above, on the operating principle of the scroll compressor, the pressure in the compression chamber formed by the orbiting wrap and the fixed wrap continuously changes during the compression process. Thus, the pressure at any point in the orbiting wrap also changes continuously within one compression cycle.

For example, when the back pressure hole is located at the point a, the point a is held at the discharge pressure in the compression process, so that the same pressure as the discharge pressure is applied to the back pressure chamber. In this case, due to excessive back pressure, the thrust force between the bottom surface of the fixed scroll and the orbiting wrap is high, so that the loss due to friction becomes large. Since the thrust force varies depending on the load when the discharge pressure is varied depending on the compression load applied to the compressor, when the back pressure hole is formed at the point where the discharge pressure is continuously applied as in the point a, The performance of the system will be affected. Specifically, the point a corresponds to a range within the ejection opening time.

On the other hand, the point b is a point at which the discharge pressure is applied for a predetermined time during the compression process, and the intermediate pressure between the suction pressure and the discharge pressure is applied at other times. Therefore, when the back pressure hole is applied to the point b, not only an appropriate double pressure can be ensured, but even when the discharge pressure changes due to the load variation or the like, the influence due to the load fluctuation Can be offset to some extent. As a result of research conducted by the present inventor, it has been confirmed that the point b corresponds to a range within 180 degrees of the intellectual retardation from the discharge opening time of the orbiting wrap.

In the case of the point c, in the case of forming the back pressure hole at the point c at which only the intermediate pressure is continuously applied during the compression process, it is difficult to obtain a sufficient degree of sealing because the back pressure is too low, Is high.

FIG. 6 is a graph showing thrust forces generated under low load, overload, high differential pressure and high pressure ratio conditions when the back pressure holes are located at positions a and b, respectively. Referring to FIG. 6, it can be seen that the thrust force is excessively generated at the low load condition when the back pressure hole is located at a, and the thrust force deviation is large in each case. On the other hand, when the back-pressure hole is located at b, relatively low thrust force is generated at low load condition, and the variation of thrust force is relatively small in each case.

On the other hand, unlike the first embodiment, it is also possible to consider an example in which the key-shaped portion is divided into separate members. 7, a keyhole 56a is additionally formed on the bottom surface of the lap flange 54 and a key (not shown) is inserted into the keyhole 56a of the lap flange and the keyhole 66 of the base flange 70 may be additionally included. In this case, the width of the keyhole 66 formed in the base flange may be smaller than the width of the key 70, and the key may be press-fitted into the keyhole.

An example of using a pin in addition to the above key may also be considered. That is, as shown in FIG. 8, three fins 80 spaced apart at an interval of 120 degrees are integrally formed on the upper surface of the base flange 64, (Not shown) is formed on the bottom surface of the lap flange 54 so that the both can be coupled.

Claims (12)

case;
A fixed scroll installed in the case;
A lap portion having a lap flange formed integrally with the orbiting lap at a lower portion and formed in a disc shape;
A base portion positioned to face the bottom surface of the lap flange and having a base flange formed in a disc shape at a lower portion thereof;
Engaging means for movably coupling the wrap portion to the fixed scroll side with respect to the base portion;
A driving motor coupled to a back surface of the base portion to eccentrically rotate the base portion and the wrap portion; And
And a main frame supporting the base unit and installed in the case,
Wherein a key-shaped portion protruding downward is formed on both sides of the bottom surface of the lap flange, a keyhole having a groove shape is formed on both sides of the upper surface of the base flange,
The key feature is positioned to be inserted into the keyhole to limit radial or circumferential movement of the wrap,
A back pressure chamber communicating with the compression chamber and a sealing means sealing the back pressure chamber are interposed between the lap portion and the base portion,
A back pressure hole passing through the wrap portion communicates the back pressure chamber and the compression chamber,
Wherein a discharge pressure is applied to the back pressure hole for a predetermined time during compression by the fixed scroll and the lap portion and an intermediate pressure defined by a value between the discharge pressure and the suction pressure is applied after a predetermined time,
Wherein the back pressure hole is formed at a position on the orbiting wrap within an in-phase phase difference of 180 degrees from the discharge opening time of the orbiting wrap. delete The method according to claim 1,
Wherein the key-shaped portion is press-fitted into one side of the bottom surface of the lap flange. The method according to claim 1,
And the key-shaped portion is integrally formed on the bottom surface of the lap flange. delete delete delete delete Fixed scroll;
And a base flange disposed opposite to a bottom surface of the lap flange, wherein the lap flange is integrally formed with the orbiting wrap at a lower portion thereof; A revolving scroll in which the lap is movably coupled to the fixed scroll side;
Engaging means for engaging the orbiting wrap to the orbiting scroll; And
And pressurizing means for introducing a part of the working fluid of the compression chamber to generate a discharge pressure for moving the orbiting wrap to the fixed scroll side,
On both sides of the bottom surface of the lap flange, an upwardly concave groove-shaped keyhole is formed,
A keyhole recessed in a downward direction is formed on both side edges of the upper surface of the base flange,
Each of the keyholes being positioned so as to be fitted with a key-shaped portion to limit radial and circumferential movement of the lap flange and the base flange,
A back pressure chamber communicating with the compression chamber and a sealing means sealing the back pressure chamber are interposed between the lap portion having the lap flange and the base portion having the base flange,
A back pressure hole passing through the wrap portion communicates the back pressure chamber and the compression chamber,
Wherein during a compression stroke of the fixed scroll and the lap portion, a discharge pressure is applied to the back pressure hole for a predetermined time, and an intermediate pressure defined as a value between the discharge pressure and the suction pressure is applied after a predetermined time,
Wherein the back pressure hole is formed at a position on the orbiting wrap within an in-phase phase difference of 180 degrees from the discharge opening time of the orbiting wrap. delete 10. The method of claim 9,
Wherein the key-shaped portion is press-fitted to one of the orbiting scroll and the orbiting wrap. 10. The method of claim 9,
Wherein the key-shaped portion is integrally formed on either the orbiting scroll or the orbiting wrap.

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