KR20100096791A - Scoroll compressor and refrigsrator having the same - Google Patents

Abstract

PURPOSE: A scroll compressor and a freezing device using the same are provided to prevent the refrigerant flowing into a middle compression chamber from a freezing cycle through an injection path, from becoming quickly discharged from the middle compression chamber to a back pressure chamber. CONSTITUTION: A scroll compressor comprises a pair of compression chambers. A part of the refrigerant compressed by the compression chamber is bypassed to a back pressure chamber(S3) formed on the back side of any one of a plurality of scrolls to support the scroll and a part of the refrigerant discharged from the compression chamber to a freezing cycle is injected from the freezing cycle to a middle compression chamber. Phase difference of at least 30° occurs between the angle at which the refrigerant starts to be injected from the freezing cycle to the middle compression chamber and the angle at which the refrigerant starts to be discharged from the compression chamber to the back pressure chamber. The temperature of the refrigerant inserted to the middle compression chamber is lower than the exit temperature of a condenser.

Description

SCROLL COMPRESSOR AND REFRIGSRATOR HAVING THE SAME}

The present invention relates to a scroll compressor for bypassing a refrigerant from an intermediate compression chamber to an intermediate compression chamber in the middle of a refrigeration cycle and to a refrigerant compressor from the intermediate compression chamber to a back pressure chamber, and a refrigerating device to which the same is applied.

Generally, a scroll compressor is a compressor which compresses refrigerant gas by changing the volume of the compression chamber formed by a pair of opposing scrolls. Scroll compressors are more efficient than reciprocating compressors or rotary compressors, have low vibration and noise, are compact and lightweight, and thus are widely used in air conditioners.

The scroll compressor may be classified 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 then discharged into the inner space of the casing, and the entire inner space of the casing is a discharge space.

The scroll compressor may also be classified into a tip seal method and a back pressure method by a sealing method of a compression chamber. That is, the tip seal method is a method in which a tip seal is installed at the lap end of each scroll so that the tip seal floats while the compressor is in operation and is in close contact with the hard plate portion of the opposite scroll. On the other hand, in the back pressure method, a back pressure chamber is formed on the rear surface of one scroll and the oil or refrigerant of medium pressure is induced in the back pressure chamber so that the scroll is pressed against the opposite scroll by being pushed by the pressure in the back pressure chamber. Generally, the tip seal method is applied to a low pressure scroll compressor, while the back pressure method is applied to a high pressure scroll compressor.

In addition, the scroll compressor may be classified into a fixed capacity type and a variable capacity type by the circulation method of the refrigerant. In other words, in the fixed capacity type, the entire refrigerant discharged from the compressor is circulated through the refrigeration cycle consisting of the condenser, the expander, and the evaporator and sucked to the suction side of the compressor. Bypass is introduced again into the intermediate compression chamber of the compressor and the rest is sucked through the refrigeration cycle to the suction side of the compressor. In general, the variable displacement scroll compressor pipes the injection pipe at the outlet of the condenser, communicates the injection pipe to the intermediate compression chamber of the compressor, and circulates the refrigerant in the middle of the injection pipe or at the point where the injection pipe is piped. Valves are installed to control this.

However, in the conventional scroll compressor as described above, when the back pressure passage communicating from the intermediate compression chamber to the back pressure chamber and the injection passage communicating from the outlet of the condenser to the intermediate compression chamber of the compressor are provided together, the distance between the back pressure passage and the injection passage is The effect on the performance of the compressor was overlooked. That is, since the refrigerant having an intermediate pressure flows into the intermediate compression chamber of the compressor through the injection passage in the refrigeration cycle, when the back pressure passage and the injection passage are disposed too close to the traveling direction of the compression chamber, the medium pressure introduced into the injection passage. The refrigerant flows rapidly into the back pressure chamber through the back pressure passage, and the pressure in the back pressure chamber is excessively increased, which causes the scroll supported by the pressure in the back pressure chamber to scroll while the pressure in the back pressure chamber is not properly maintained. Too close contact with the friction loss is generated, as well as the wear of the wrap may cause a problem that the reliability of the compressor is lowered.

The present invention solves the problems of the conventional scroll compressor as described above, and prevents the refrigerant injected into the intermediate compression chamber in the refrigeration cycle through the injection passage to prevent the rapid leakage from the intermediate compression chamber to the back pressure chamber of the back pressure chamber SUMMARY OF THE INVENTION An object of the present invention is to provide a scroll compressor and a refrigerating device having the same, which can maintain a proper pressure.

In order to achieve the object of the present invention, two pairs of compression chambers are formed in which a plurality of scrolls are engaged and continuously move while performing relative movement, and a part of the refrigerant compressed in the compression chamber is any one of the plurality of scrolls. A scroll compressor, which is bypassed to a back pressure chamber provided on two backs of a scroll, supports the scroll, and a portion of the refrigerant discharged from the compression chamber to the refrigeration cycle is injected into the intermediate compression chamber from the refrigeration cycle. There is provided a scroll compressor which is formed to have a phase difference of at least 30 ° between an angle at which P starts to be injected and an angle at which refrigerant in the compression chamber begins to be back pressured to the back pressure chamber.

In addition, fixed scroll; And a swing scroll which is engaged with the fixed scroll to form two pairs of compression chambers which are continuously moved while swinging. The back pressure of the swing scroll includes a back pressure chamber for receiving refrigerant bypassed from the compression chamber. Is formed, the fixed scroll is formed with at least one back pressure passage for communicating between the compression chamber and the back pressure chamber, one side of the back pressure passage is to allow a portion of the refrigerant discharged from the compression cycle to the intermediate compression chamber in the compression chamber. An injection passage is formed, and the back pressure passage is provided with a scroll compressor that is formed relatively closer to the suction side of the compression chamber than the injection passage.

In addition, a compressor; A condenser connected to the discharge side of the compressor; An expander coupled to the condenser; And an evaporator connected to the inflator and connected to the suction side of the compressor, wherein the compressor has a scroll formed such that an injection passage communicating with the intermediate compression chamber in the middle of the refrigerating cycle has a phase difference of approximately 30 ° or more with the back pressure passage. There is provided a refrigeration apparatus consisting of a compressor.

The scroll compressor according to the present invention and the refrigerating device having the same prevent proper flow of refrigerant injected into the intermediate compression chamber from the refrigeration cycle through the injection passage from the intermediate compression chamber to the back pressure chamber to properly adjust the pressure in the back pressure chamber. Not only can it be maintained, but also the amount of refrigerant in the compression chamber can be increased to improve the performance of the scroll compressor and the refrigerating apparatus having the same.

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

As shown in FIG. 1, the high-pressure scroll compressor according to the present invention includes a casing 10 having a sealed inner space, a main frame 20 and a sub which are respectively fixed to upper and lower inner spaces of the casing 10. A frame (not shown), a drive motor 30 mounted between the main frame 20 and a subframe (not shown) and generating rotational force, and fixedly installed on an upper surface of the main frame 20 and the gas suction pipe. A fixed scroll 40 to which the SP is directly coupled, and a pivoting scroll 50 rotatably mounted on an upper surface of the main frame 20 to form a compression chamber P by engaging the fixed scroll 40. It is installed between the turning scroll 50 and the main frame 20 includes an Oldham's ring (not shown) for turning while preventing the turning scroll 50 from rotating.

The casing 10 has a sealed inner space divided into an upper space S1 and a lower space S2 by the main frame 20 and the fixed scroll 40, and the upper space S1 and the lower space ( S2) maintains a high pressure state, and the bottom surface of the casing 10 (S2) is filled with oil. The gas suction pipe SP is coupled to the upper space S1 of the casing 10, and the gas discharge pipe DP is connected to the lower space S2 of the casing 10.

The main frame 20 has a bearing hole 21 formed in the center thereof, and an oil pocket 22 is formed at the upper end of the bearing hole 21 so that oil drawn up through the drive shaft 32 to be described later is collected. do. In addition, a back pressure groove 23 is formed at an upper edge of the main frame 20 to form a back pressure chamber S3 having a medium pressure by mixing a part of the refrigerant sucked with a part of the oil sucked up, and the back pressure groove 23. Inside the seal member 60 is inserted into a sealing groove (unsigned) is formed in an annular shape to seal the oil accumulated in the oil pocket 22 to maintain a high pressure. The back pressure chamber S3 is a space in which the back pressure groove 23 of the main frame 20 and the hard plate portion 41 of the fixed scroll 40 to be described later and the hard plate portion 51 of the turning scroll 50 to be described later are combined. To form.

The drive motor 30 is fixed to the inside of the casing 10 and is disposed with a stator (not shown) having a coil 31 and a predetermined gap inside the stator 31 to receive power from the outside. Rotor (not shown) that rotates while interacting with the stator, and the drive shaft 32 is coupled to the rotor in a shrink fit to transmit the rotational force of the drive motor 30 to the swing scroll (50). The drive shaft 32 has an oil passage 32a formed therethrough in the axial direction, and an oil pump (not shown) is installed at a lower end of the oil passage 32a.

The fixed scroll 40 is formed on the bottom surface of the hard plate portion 41, the fixed wrap 42 constituting a pair of two compression chamber (P) in a spiral form, the side of the hard plate portion 41 is the gas suction pipe A suction port 43 is formed in which SP directly communicates, and a discharge port 44 for discharging the compressed refrigerant into the upper space S1 of the casing 10 is formed at the center of the upper surface of the hard plate part 41. The compression chamber P and the back pressure chamber S3 are disposed between the lap and the lap forming the compression chamber P at the bottom surface of the hard plate part 41, that is, the surface forming the thrust bearing surface together with the turning scroll 50. The back pressure passage 110 is formed to communicate.

As shown in FIGS. 2 to 4, the back pressure passage 110 includes a first back pressure hole 111 communicating with the back pressure chamber S3 and a second back pressure hole 112 communicating with the compression chamber P. And a third back pressure hole 113 formed at a predetermined depth in the radial direction on the outer circumferential surface of the fixed scroll 40 so that the first back pressure hole 111 and the second back pressure hole 112 communicate with each other. The first back pressure hole 111 may be smoothly communicated with the back pressure groove 23 at the outlet end of the first back pressure hole 111, that is, the surface facing the back pressure groove 23. A communication groove 114 wider than the hole 111 is formed. The communication groove 114 may be formed in a radially long rectangular shape or may be formed in a circular groove wider than the first back pressure hole 111. In addition, the diameters d1, d2, and d3 of the back pressure holes 111, 112, and 113 may be formed to be substantially the same, so that the flow path resistance may be reduced.

The first back pressure hole 111, the second back pressure hole 112, and the third back pressure hole 113 are formed to form one flow path, and the one flow path alternates with the pair of compression chambers P. It is formed to communicate. That is, one second back pressure hole 112 is formed, and the second back pressure hole 112 is formed to be positioned at the center between neighboring fixing wraps 42 and in the inner compression chamber according to the pressure difference. As shown in FIG. 4, the inner diameter d1 of the second back pressure hole 112 is preferably not greater than the wrap thickness t of the turning scroll so that the refrigerant does not leak into the outer compression chamber.

A blocking member 115 is coupled to the third back pressure hole 113 so that the third back pressure hole 113 is separated from the inner space of the casing 10 by a predetermined depth inserted at an outer end thereof. The blocking member 115 may be press-fitted into a non-ferrous metal having a relatively elasticity and sealed or may be fastened to a predetermined depth by using a metal bolt provided with a thread as shown in FIGS. 3 and 4. In the case where the metal bolt is used, it may be preferable to seal the head of the metal bolt by sealing sealing 116.

As shown in FIG. 2, the turning scroll 50 forms a pair of compression chambers P together with the fixing wrap 42 of the fixed scroll 40 on the upper surface of the hard plate portion 51 ( 52 is formed in a spiral shape, and a boss portion 53 is coupled to the driving shaft 32 at the center of the bottom surface of the hard plate portion 51 to receive the power of the driving motor 30.

Here, the fixed wrap 42 and the swing wrap 52 may be formed symmetrically with the same wrap length, the wrap length is different, that is, the swing wrap is formed in an asymmetric shape about 180 ° long It may be.

The scroll compressor of the present invention as described above operates as follows.

That is, when power is applied to the drive motor 30, the drive shaft 32 rotates with the rotor to transmit a rotational force to the turning scroll 50, the rotational scroll 50 received this rotational force Is rotated by an eccentric distance from the upper surface of the main frame 20 by the Oldham ring 60 between the fixed wrap 42 of the fixed scroll 40 and the turning wrap 52 of the orbiting scroll 50. A pair of compression chambers P continuously moving are formed in the. In addition, the compression chamber P moves to the center by the continuous swing motion of the swing scroll 50 to compress the refrigerant sucked by the volume decrease.

At the same time, in the oil pump (not shown) installed at the lower end of the drive shaft 32 to pump the oil filled in the casing 10, the oil is the upper end through the oil passage 32a of the drive shaft 32 While some of the oil is supplied to the bearing hole 21 of the main frame 20, some of the oil is scattered from the upper end of the driving shaft 32 and flows into the back pressure chamber S3 of the main frame 20. . The oil flowing into the back pressure chamber S3 supports the turning scroll 50 so that the turning scroll 50 rises toward the fixed scroll 40, and thus the fixed wrap 42 and the turning wrap 52. The compression chamber P is sealed while being in close contact with each of the hard plate portions 51 and 41 corresponding thereto.

In this state, the turning scroll 50 continuously compresses the refrigerant, and a portion of the compressed refrigerant moves to the back pressure chamber S3 through the back pressure passage 110 to move the back pressure chamber. The pressure of S3 is kept constant. Here, only one outlet of the back pressure passage 110, that is, the second back pressure hole 112 is formed, but the second back pressure hole 112 is disposed in both compression chambers P with the turning wrap 52 interposed therebetween. As each alternately communicated, the oil may be uniformly supplied to each compression chamber P through the back pressure passage 110.

On the other hand, when the scroll compressor is a variable displacement type, the compression capacity of the scroll compressor is increased by reflowing the refrigerant into the intermediate compression chamber of the compressor in the middle of the refrigerating cycle including the scroll compressor, that is, at the outlet of the condenser. You can.

For example, as shown in FIG. 8, an injection pipe 6 is formed in the middle of the refrigerant pipe 5 connecting the condenser 2 and the expander 3 of the refrigerating cycle, that is, at the outlet side of the condenser 2. The injection pipe 6 is connected to the injection passage 120 provided in the fixed scroll 40 of the scroll compressor 1 shown in FIGS. 1 and 2. A bypass valve 7 for controlling the flow of the refrigerant may be installed at the middle of the injection pipe 6 or at a point where the injection pipe 6 is branched.

As illustrated in FIGS. 2 and 3 and 5, the injection passage 120 includes a first injection hole 121 formed at a predetermined depth in the radial direction on the outer circumferential surface of the fixed scroll 40, and the first injection hole 121 formed therein. It consists of the 2nd injection hole 122 formed in the axial direction so that it may penetrate into the said intermediate | middle compression chamber at the nearly end of the 1st injection hole 121. As shown in FIG.

In this case, the second injection hole 122 may leak refrigerant into the back pressure chamber S3 depending on the formation position of the second injection hole 122, thereby degrading the performance of the compressor. Therefore, the position where the injection passage 120 is formed with respect to the back pressure passage 110, more precisely, the second back pressure hole 112 of the back pressure passage 110 and the second injection hole 122 of the injection passage 120. ) Position is important for improving the performance of the compressor.

To this end, the second injection hole 122 of the injection passage 120 is the angle at which the refrigerant begins to be injected into the intermediate compression chamber (P) of the compressor 1 in the refrigeration cycle and the angle of the intermediate compression chamber (P). The angle at which the refrigerant begins to be back-pressured into the back pressure chamber S3, that is, closer to the discharge side of the compression chamber than the second back pressure hole 112 of the back pressure passage 110 as shown in FIGS. 6 and 7, more precisely at least It is preferable that the coolant injected into the intermediate compression chamber through the injection passage 120 can be effectively prevented from leaking into the back pressure passage 110. The larger the phase difference α between the second back pressure hole 112 of the back pressure passage 110 and the second injection hole 122 of the injection passage 120 may be preferable.

In addition, the second injection hole 122 may be formed to be substantially the same as the diameter of the second back pressure hole 112 so that the injection amount of the refrigerant may be smooth. And the diameter (d4) of the second injection hole 122 is formed so as not to be larger than the thickness (t) of the turning wrap 52 of the turning scroll 50 is the refrigerant injected through the injection passage 120 It may be desirable to communicate with both compression chambers together to prevent leakage of refrigerant.

The temperature of the refrigerant injected into the intermediate compression chamber may be lower than that of the outlet side of the condenser 2 and higher than the suction side temperature of the compression chamber. That is, after the refrigerant discharged from the scroll compressor (1) passes through the condenser (2), a part of the refrigerant is bypassed to the injection pipe (6) at the outlet of the condenser (2), and the bypassed high temperature and high pressure The liquid refrigerant is expanded and converted into a mixed refrigerant (gas refrigerant + liquid refrigerant) of approximately 20 ° C., and the mixed refrigerant is exchanged with the condenser 2 to be converted into a low temperature gas refrigerant, and the low temperature gas refrigerant is Pipes are formed to be injected into the intermediate compression chamber through the injection passage (120).

As described above, in a scroll compressor having the back pressure passage 110 and the injection passage 120, the interval between the back pressure passage 110 and the injection passage 120 has a phase difference α of at least 30 ° or more. As shown in 9 (b), the actual pressure of the back pressure chamber is almost similar to the design pressure, so that the turning scroll can be stably supported. If the distance between the back pressure passage and the injection passage is 20 °, as shown in FIG. 9 (b), the actual pressure of the back pressure chamber is higher than the design pressure, so that the turning scroll excessively rises, thereby causing the turning. Friction loss or abrasion between the scroll and the fixed scroll may occur, thereby degrading the performance or reliability of the compressor.

In this way, the gap between the injection passage and the back pressure passage maintains an appropriate phase difference so that the refrigerant injected into the intermediate compression chamber through the injection passage does not move along the traveling direction of the compression chamber but leaks into the back pressure chamber through the back pressure passage. You can prevent it. In this way, the refrigerant injected into the intermediate compression chamber through the injection passage in the middle of the refrigeration cycle during the high capacity operation of the scroll compressor is combined with the refrigerant sucked to the suction side of the compression chamber to increase the amount of refrigerant, thereby improving the performance of the scroll compressor. Can be.

On the other hand, when the scroll compressor according to the present invention is applied to a refrigerator, the efficiency of the refrigerator can be improved.

For example, as shown in FIG. 8, the refrigerator 700 of the present invention includes a scroll compressor 1, a condenser 2, an expander 3, and an evaporator 4, and a part of the refrigerant passing through the condenser 2. It is made of a refrigerant compression type refrigeration cycle including an injection flow path to be injected into the intermediate compression chamber of the scroll compressor (1) again. In addition, the scroll compressor 1 is connected to the main board 710 for controlling the overall operation of the refrigerator 700, and the fixed scroll is installed in the scroll compressor 1 in the freezer 700. It forms a back pressure passage for flowing out the refrigerant from the intermediate compression chamber to the back pressure chamber and an injection passage for reflowing the refrigerant from the condenser outlet to the intermediate compression chamber. The gap between the back pressure passage and the injection passage may be formed to be at least 30 ° as described above. In this way, the refrigerant injected into the intermediate compression chamber through the injection passage can be prevented from leaking through the back pressure passage, so that the performance of the refrigeration apparatus having the scroll compressor can be improved.

The scroll compressor according to the present invention can be widely used in refrigeration machines such as air conditioners.

1 is a longitudinal sectional view showing a part of the scroll compressor of the present invention;

FIG. 2 is a perspective view of the compression unit broken in the scroll compressor according to FIG. 1; FIG.

3 is a cross-sectional view taken along line "I-I" of FIG.

4 is a longitudinal sectional view showing an enlarged back pressure passage in the scroll compressor according to FIG. 3;

5 is a longitudinal cross-sectional view showing an injection passage in the scroll compressor according to FIG. 3;

FIG. 6 is a sectional view taken along the line “II-II” of FIG. 2;

7 is an enlarged view illustrating a phase difference between the back pressure passage and the injection passage in FIG. 6;

8 is a system diagram showing a refrigeration cycle equipped with a scroll compressor of the present invention,

9 is a graph showing a change in back pressure chamber pressure of a scroll compressor according to a phase difference between a back pressure passage and an injection passage in a refrigeration cycle according to FIG. 8;

10 is a schematic view showing one embodiment of an air conditioner to which the scroll compressor according to FIG. 1 is applied.

** Description of symbols for the main parts of the drawing **

1: scroll compressor 2: condenser

3: expander 4: evaporator

5: refrigerant tube 6: injection tube

7: bypass valve 10: casing

20: main frame 23: back pressure groove

40: fixed scroll 41: fixed scroll plate portion

42: fixed wrap 50: turning scroll

51: turning scroll plate 110: back pressure passage

111, 112, 113: Back pressure hole 120: Injection passage

121: first injection hole 122: second injection hole

Claims (8)

Two pairs of compression chambers are formed in which a plurality of scrolls are engaged and move in a relative motion while a relative movement is performed, and a portion of the refrigerant compressed in the compression chamber is bypassed to the back pressure chamber provided on the rear of any one of the plurality of scrolls. A scroll compressor in which a portion of the refrigerant discharged from the compression chamber into the refrigeration cycle is injected into the intermediate compression chamber in the refrigerating cycle, And a phase difference of at least 30 ° between an angle at which the refrigerant starts to be injected into the intermediate compression chamber from the refrigeration cycle and an angle at which the refrigerant in the compression chamber begins to be backpressured into the back pressure chamber. The method of claim 1, And a temperature of the refrigerant injected into the intermediate compression chamber is lower than a temperature at the outlet side of the condenser. The method of claim 2, And a temperature of the refrigerant injected into the intermediate compression chamber is higher than a suction side temperature of the compression chamber. Fixed scroll; And Includes; the swing scroll to form a pair of compression chambers that are continuously moved while engaging the fixed scroll to the swing movement; The back pressure chamber is formed on the back of the swing scroll to accommodate the refrigerant bypassed from the compression chamber, The fixed scroll is formed with at least one back pressure passage communicating between the compression chamber and the back pressure chamber, An injection passage is formed at one side of the back pressure passage to allow a portion of the refrigerant discharged from the compression chamber to the intermediate compression chamber. And the injection passage is formed closer to the discharge side of the compression chamber than the back pressure passage. The method of claim 4, wherein And a distance between the back pressure passage and the injection passage is formed such that the phase difference is approximately 30 degrees or more. The method of claim 4, wherein And the diameter of the injection passage is formed so that the diameter of the back pressure passage is not small. The method of claim 6, And the injection passage is formed on both scrolls so as not to be larger than the thickness of the wrap forming the compression chamber. compressor; A condenser connected to the discharge side of the compressor; An expander coupled to the condenser; And And an evaporator connected to the inflator and connected to the suction side of the compressor. The compressor comprises a scroll compressor of any one of claims 1 to 7.

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