KR101368396B1 - Scroll compressor - Google Patents

Abstract

The present invention relates to a scroll compressor. The present invention, by forming a guide hole in one of the wrap portion and the base portion and the guide pin is inserted into the guide hole on the other side, it is easy to process the guide pin and guide hole for coupling the wrap portion and the base portion The cost can be reduced and the precision can be processed, which can prevent the swing scroll from becoming unstable. In addition, since the guide pin and the guide hole are formed in a circular cross-sectional shape, wear of the guide pin or the guide hole can be prevented in advance.

Description

[0001] SCROLL COMPRESSOR [0002]

TECHNICAL FIELD The present invention relates to scroll compressors and, more particularly, to scroll compressors having a split swing scroll.

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 be classified into a tip seal method and a back pressure method according to the sealing method of the 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.

However, in the conventional scroll compressor as described above, as both sides of the swing scroll are rotated in contact with the fixed scroll and the main frame, the shape of the swing scroll must be accurately processed to suppress the vibration of the swing scroll, The loss due to this can be minimized. To this end, after the pre-working the bearing surface in contact with the main frame was to wrap the wrap portion, this has caused a long work time and the bearing surface may be damaged during the processing of the wrap portion. In addition, since the shape and size of the rotating scroll and the fixed scroll, in particular the wrap portion according to the capacity of the compressor to be different, there is a problem that takes a considerable time to design and manufacture the rotating scroll.

In addition, the pressure at which the bearing surface of the turning scroll presses the bearing surface of the fixed scroll varies according to the pressure applied to the back pressure chamber. Therefore, in order to reduce the frictional force while preventing the leakage of the refrigerant, the pressure applied to the back pressure chamber must be properly maintained. However, since the scroll compressor must support the entire turning scroll at the pressure in the back pressure chamber, a considerable amount of high pressure must be applied to the back pressure chamber, and in the case where the pressure in the back pressure chamber is fluctuated, the scroll compressor has a large adhesion to the fixed scroll. There is a problem that affects. In particular, the pressure of the back pressure chamber is affected by the discharge pressure. Since the discharge pressure varies depending on the load applied to the compressor, the sealing performance and frictional loss between the swing scroll and the fixed scroll are affected by the load fluctuation. There was also a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a scroll compressor that can easily produce a swing scroll.

In addition, another object of the present invention is to provide a scroll compressor capable of obtaining sufficient sealing performance while minimizing frictional loss between the turning scroll and the fixed scroll even if there is a load variation.

In order to achieve the object of the present invention, the case; A fixed scroll installed in the case; A wrap part engaged with the fixed scroll to form a compression chamber; A base part coupled to the wrap part to support the wrap part so as to be movable toward the fixed scroll side; A driving motor coupled to a rear surface of the base part to eccentrically rotate the base part and the wrap part; And a main frame supporting the base part in the axial direction and installed in the case, wherein one of the wrap part and the base part has a plurality of guide pins formed in the axial direction, and the other side of the guide pin is provided. There is provided a scroll compressor in which a guide hole is formed so as to slide in an axial direction.

Here, the guide pin may be formed so that its outer peripheral surface is curved, the guide hole is formed to correspond to the guide pin.

In the scroll compressor according to the present invention, by combining the wrap portion and the base portion with a plurality of pins, the processing of the guide pin and the guide hole for joining the wrap portion and the base portion is easy, and the cost can be reduced and precisely processed. This instability can be prevented beforehand. In addition, since the guide pin and the guide hole are formed in a circular cross-sectional shape, wear of the guide pin or the guide hole can be prevented in advance.

1 is a cross-sectional view showing a first embodiment of a scroll compressor according to the present invention;
2 is an enlarged partial cutaway view of the compression mechanism according to FIG. 1;
3 is an exploded perspective view showing a turning scroll according to FIG. 1;
4 is an enlarged cross-sectional view of the turning scroll according to FIG. 1;
5A to 5C are plan views schematically illustrating a process in which the first embodiment shown in FIG. 1 operates.

Hereinafter, the scroll compressor according to the present invention will be described in detail with reference to the embodiments shown in the accompanying drawings.

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

As shown in Figures 1 to 3, the scroll compressor according to the present invention, the inner space of the case 1 is divided into a suction space 11 of the low pressure portion and the discharge space 12 of the high pressure portion, the case (1) A driving motor 2 for generating a rotational force is installed in the suction space 11 of the), and the main frame 3 is fixedly installed between the suction space 11 and the discharge space 12 of the case 1. A fixed scroll 4 is fixedly installed on an upper surface of the main frame 3, and is eccentrically coupled to the crank shaft 23 of the drive motor 2 between the main frame 3 and the fixed scroll 4. The swinging scroll 5 which forms two pairs of compression chambers P which move continuously with the fixed scroll 4 is installed so that rotation is possible. The old dam ring 6 is installed between the main frame 3 and the turning scroll 5 to prevent the rotating scroll 5 from rotating.

The suction tube 13 is coupled to the suction space 11 of the case 1 while the discharge tube 14 is coupled to the discharge space 12.

Here, although not shown in the drawings, the case is provided with a predetermined discharge space sealed and the suction space is a low pressure portion and the discharge space is a high pressure portion by a discharge plenum fixedly coupled to the fixed scroll (4), or The inner space of the case may be divided into a suction space and a discharge space by a high and low pressure separator (not shown) fixed to an upper surface of the fixed scroll and in close contact with an inner circumferential surface of the case.

The fixed scroll (4) is projected on the bottom surface of the hard plate portion 41 is formed with a fixed wrap 42 in the involute shape to form a compression chamber (P) together with the turning wrap (52) of the turning scroll (5). . A suction port (not shown) is formed on the outer circumferential surface of the hard plate portion 41 of the fixed scroll 4 so that the suction space 11 and the compression chamber P of the case 1 communicate with each other. A discharge port 44 is formed in the center of the hard plate part 41 so that the compression chamber P and the discharge space 12 of the case 1 communicate with each other. In the figure, 7 is a subframe, 8 is a discharge valve, 21 is a stator, and 22 is a rotor.

In the scroll compressor according to the present embodiment as described above, the refrigerant flows into the suction space 11, which is the low pressure part of the case 1, from the refrigeration cycle through the suction pipe 13, and the low pressure refrigerant of the suction space 11 is fixed. It is introduced into the compression chamber through the suction port of the scroll 4 and is compressed while moving to the center of the swing scroll and the fixed scroll by the swing scroll 5, and then through the discharge port 44 of the fixed scroll 4, the case (1). A series of processes to be discharged to the discharge space 12 of the) is repeated.

Here, the turning scroll of the scroll compressor according to the present embodiment is composed of a wrap part 50 engaged with the fixed scroll, and a base part 60 coupled with the wrap part 50.

The wrap part 50 is composed of a turning wrap 52 which is engaged with the fixed wrap 42 to form a compression chamber, and a wrap flange 54 which is integrally formed with the turning wrap 52. The wrap flange 54 has a disc shape, and a plurality of guide holes 56 are formed on the outer side of the turning wrap 52 to be coupled to the base portion 60 along the circumferential direction. The guide hole 56 may be formed in a circular hole shape to correspond to the guide pin 66 to be described later.

The base portion 60 is coupled to the wrap portion 50 in a state facing the bottom surface of the wrap flange 54, specifically, the base flange 64 is formed to have a disk shape similar to the wrap flange 54 And a boss portion 68 formed on the bottom surface of the base flange 64 to be engaged with the crankshaft 23 described above.

In addition, a plurality of guide pins 66 are formed at edges of the upper surface of the base flange 64 to be slidably inserted into the guide holes 56 in the axial direction. When the guide pin 66 is slidably inserted into the guide hole 56 in the axial direction, the wrap part 50 is movable in the axial direction of the crankshaft with respect to the base part 60, but the base part It is combined such that it cannot move in the radial or circumferential direction. However, since the axial movement of the wrap part 50 is limited by the distance between the fixed scroll and the main frame 3, the guide pin 66 is inserted into the guide hole 56. Will be maintained. That is, the two can be stably coupled by simply inserting the guide pin into the guide hole without using a bolt fastening or welding method.

In addition, the guide pin 66 and the guide hole 56 can be easily processed to reduce the cost and can be precisely processed to prevent the unstable behavior of the turning scroll (5). In addition, as the guide pin 66 and the guide hole 56 are formed in a circular cross-sectional shape, the driving force of the driving motor is received by the base part 60 when the base part 60 is transferred to the wrap part 50. The load applied is distributed relatively uniformly to prevent wear of the guide pin 66 or the guide hole 56 in advance.

On the other hand, the Oldham ring 6 as the anti-rotation mechanism described above is coupled to the bottom of the base portion 60. Specifically, the old dam ring 6 includes a ring-shaped portion 6a that is in contact with the bottom surface of the base flange 64, and both sides of the ring-shaped portion 6a have a phase difference of 180 degrees. First projections 6b are formed. The first protrusion 6b is inserted into the first protrusion groove 3a formed in the main frame 3. In addition, two second protrusions 6c are formed on both sides of the upper surface of the ring-shaped portion 6b in the state of having a phase difference of 180 degrees. The second protrusion 6c is inserted into the second protrusion grooves 64a respectively formed on the bottom surface of the base flange 64.

Through this, even if the rotational force of the crankshaft 23 is transmitted to the base portion 60, the base portion 60 is rotated by the old dam ring 6 in a state where the rotation is prevented, the base portion Wrap portion 50 coupled to the radial movement is limited to 60 is also pivoted with the base portion (60).

On the other hand, a back pressure chamber 62 partitioned by a seal 62a is formed on the upper surface of the base flange 64. Referring to FIG. 4, the back pressure chamber 62 is positioned between the bottom surface of the wrap flange 54 and the top surface of the base flange 64 and is inserted into and fixed to the base flange 64. The inner space of the back pressure chamber 62 is blocked from the low pressure space 11. The back pressure hole 54a communicates between the inner space of the back pressure chamber 62 and the compression chamber. It is formed through the flange 64.

Therefore, a portion of the compressed refrigerant present in the compression chamber is introduced into the back pressure chamber through the back pressure hole 54a in the process of sucking and compressing the refrigerant. Since the internal pressure of the back pressure chamber is higher than the pressure around the base flange 64, the base portion 60 rises along the axial direction from the wrap portion 50, through which the bottom of the fixed scroll and the pivot Sealing is made between the wraps 52.

The internal pressure of 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 swing wrap 52 of the swing scroll, and the pressure inside the back pressure chamber decreases as it moves outside.

5A to 5C are plan views schematically illustrating a process of compressing the refrigerant by the turning wrap and the fixed wrap, and the solid line corresponds to the center line of the fixed wrap 42 and the dotted line corresponds to the center line of the swing wrap 52, respectively. . 5C corresponds to the case where the pressure in the compression chamber reaches the discharge pressure and discharge starts. As described above, due to the operation principle of the scroll compressor, the pressure in the compression chamber formed by the swing wrap and the fixed wrap is continuously changed in the compression process. Thus, the pressure at any point of the turning wrap also changes continuously in one compression cycle.

For example, when the back pressure hole is at the point a, the point a is at a position maintained at the discharge pressure during 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, a high axial friction force (thrust force) between the bottom of the fixed scroll and the turning wrap is generated, the friction loss is increased. In addition, since the discharge pressure varies depending on the amount of compression load applied to the compressor, when the back pressure hole is formed at a point where the discharge pressure is continuously applied, such as point a, the axial frictional force varies depending on the load. This will affect the performance of the compressor. Specifically, the point a corresponds to a range within the discharge start time.

As illustrated in FIG. 5B, point b is a point at which a discharge pressure is applied for a predetermined time in the compression process, and an 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 back pressure can be secured, but also when the discharge pressure changes due to the load variation, etc., the buffer pressure is somewhat buffered due to the intermediate pressure. It can be offset to some extent. As a result of the present inventors, it was confirmed that the point b falls within a range of 180 degrees of the involute phase difference from the discharge start time of the turning wrap.

As shown in FIG. 5C, in the case of the point c, only the intermediate pressure is continuously applied in the compression process, and when the back pressure hole is formed at the point c, the back pressure is too low to obtain a sufficient amount of sealing, and thus the refrigerant There is a high risk of leakage.

3: main frame 4: fixed scroll
42: stationary lap 44: outlet
5: turning scroll 50: lap
52: turning wrap 54: wrap flange
56: guide hole 60: base portion
62 back pressure chamber 62a sealing
64: base flange 66: guide pin

Claims (9)

case;
A fixed scroll installed in the case;
A wrap part having a turning wrap engaged with the fixed scroll to form a compression chamber, and a wrap flange provided at one side of the turning wrap;
A base part coupled to the wrap part to support the wrap part so as to be movable toward the fixed scroll side;
A driving motor coupled to a rear surface of the base part to eccentrically rotate the base part and the wrap part; And
And a main frame supporting the base part in the axial direction and installed in the case.
One of the wrap portion and the base portion has a plurality of guide pins are formed in the axial direction, the other side is formed with a guide hole so as to slide the guide pins in the axial direction,
A back pressure chamber communicating with the compression chamber is formed between the wrap portion and the base portion, and a back pressure hole for communicating the back pressure chamber and the compression chamber is formed through the wrap flange.
And the back pressure hole is formed to be positioned at a point having a phase angle larger than α and smaller than α + 180 ° on the swing wrap when α is a discharge start time of the swing wrap. The method of claim 1,
The guide pin is formed so that its outer peripheral surface is curved, the guide hole is formed to correspond to the guide pin. delete delete delete delete delete delete 3. The method according to claim 1 or 2,
And the case is divided into two spaces having different pressures, and the wrap part and the base part are disposed in a space having a relatively low pressure among the two spaces.

Images