KR102022870B1

KR102022870B1 - Scroll compressor

Info

Publication number: KR102022870B1
Application number: KR1020130057320A
Authority: KR
Inventors: 성상훈; 김학영; 이재상
Original assignee: 엘지전자 주식회사
Priority date: 2013-05-21
Filing date: 2013-05-21
Publication date: 2019-09-20
Also published as: KR20140136797A

Abstract

The scroll compressor according to the present invention is provided with a predetermined interval in the lateral direction between the rear surface of the swing scroll and the frame to form at least one of the plurality of sealing members for forming the back pressure chamber at the same time the gas force of the compression chamber As the working point of is formed eccentrically in the discharge port direction, the working point of the back pressure is also installed in the discharge port direction, so that the moment arm, which is the distance between the working point of the back pressure and the working point of the gas force, is stabilized and This improves compression efficiency by reducing axial leakage and frictional losses.

Description

Scroll Compressor {SCROLL COMPRESSOR}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor, and more particularly, to a through shaft scroll compressor having a backing chamber sealing member in a swing scroll.

The scroll compressor forms a compression chamber in which the rotating scroll continuously moves between the fixed wrap and the rotating wrap while the fixed scroll of the fixed scroll and the rotating wrap of the rotating scroll engage with the fixed scroll, and sucks and compresses the refrigerant. It is a type of compressor.

Such a scroll compressor has a superior advantage over other types of compressors in terms of vibration and noise generated during operation since suction, compression, and discharge are continuously performed.

The behavior of the scroll compressor is determined by the shape of the fixed wrap and the swing wrap. The stationary wrap and the swiveling wrap may have any shape, but typically have the form of an involute curve that is easy to machine. An involute curve is a curve that corresponds to the trajectory that the end of the yarn draws when unwinding the yarn wound around a base circle of any radius. In the case of using the involute curve, the thickness of the lap is constant and the volume change rate is also constant. Therefore, in order to obtain a high compression ratio, the number of turns of the lap needs to be increased, but the size of the compressor also increases.

On the other hand, the turning scroll has a turning wrap is formed on one side of the disk portion in the form of a disk, the boss portion is formed on the other side (that is, the back) of the hard plate portion is not formed the turning wrap is connected to the rotating shaft for turning the turning scroll . This type can form a turning wrap over almost the entire area of the hard plate part, so that the diameter of the hard plate part can be reduced to obtain the same compression ratio, while the action point to which the refrigerant repulsive force is applied during compression and the reaction force to cancel this repulsive force The applied action point is spaced in the vertical direction, the operation of the swing scroll becomes unstable in the operation process, there is a problem that the vibration or noise increases.

As a method for solving this problem, a so-called through-through scroll compressor is disclosed in which the point where the rotating shaft 1 and the turning scroll 2 are coupled to each other is formed on the same surface as the turning wrap 2a as shown in FIG. Such a shaft-through scroll compressor can solve the problem that the swing scroll (2) is inclined because the action point of the reaction force of the refrigerant and the action point of the reaction force act on the same point.

However, in the conventional shaft-through scroll compressor as described above, a plurality of sealing members 4 and 5 are provided on the upper surface of the main frame 3 at regular intervals so that the upper surface of the main frame 3 and the turning scroll 2 Back pressure chamber (S3) is formed between the bottom of the), but as shown in Figure 2, the geometric center (CL1) of the back pressure chamber (S3) coincides with the center (CL2) of the rotation axis while compression formed around the discharge port (2b) The center CL3 of the seal pressure is eccentrically formed by a predetermined distance L1 from the center CL2 of the rotation shaft. Accordingly, as shown in FIGS. 2 and 3, the interval t1, that is, the turning scroll 2, between the operating point P3 of the back pressure forming the geometric center CL1 of the back pressure chamber and the center of gas force P4. As the moment arm with respect to the rod becomes longer, the behavior of the swinging scroll 2 becomes unstable, causing axial leakage or frictional loss of the refrigerant.

It is an object of the present invention to provide a scroll compressor capable of stabilizing the behavior of a turning scroll by reducing the distance between the acting point of back pressure and the acting point of gas force.

In order to achieve the object of the present invention, a sealed container; A fixed scroll fixed to the sealed container and having a fixed wrap formed thereon; A turning scroll having a turning wrap engaged with the fixed wrap to form a compression chamber, and a rotating shaft engaging portion coupled to the eccentric portion of the rotating shaft so as to overlap laterally with the turning wrap and pivoting with respect to the fixed scroll; A frame installed on a rear surface of the swing scroll; And a plurality of sealing members installed at a predetermined interval in a lateral direction between the rear surface of the pivoting scroll and the frame to form a back pressure chamber, wherein the first sealing member installed inside the plurality of sealing members includes the frame. While coupled to the second sealing member installed on the outside may be provided with a scroll compressor coupled to the swing scroll.

In addition, a fixed scroll is formed with a fixed wrap; A turning scroll having a turning wrap engaged with the fixed wrap to form a compression chamber, and a rotating shaft engaging portion coupled to the eccentric portion of the rotating shaft so as to overlap laterally with the turning wrap and pivoting with respect to the fixed scroll; A frame supporting a rear surface of the swing scroll; And a plurality of sealing members installed at a predetermined interval in the lateral direction between the rear surface of the swing scroll and the frame to form a back pressure chamber, wherein the plurality of sealing members are provided with a scroll compressor coupled to the swing scroll. Can be.

In the scroll compressor according to the present invention, since the action point of the gas force of the compression chamber is eccentrically formed in the discharge port direction, the moment arm, which is the distance between the action point of the back pressure and the action point of the gas force, is also moved in the discharge port direction. It is possible to improve the compression efficiency by reducing the axial leakage and friction loss by reducing the swing scroll behavior by reducing the

1 is a longitudinal sectional view showing a compression unit in a conventional shaft-through scroll compressor;
2 and 3 is a state diagram of the force distribution shown in the front and the top view showing the relationship between the back pressure and the gas force in the compression unit of the shaft-through scroll compressor according to FIG.
4 is a longitudinal sectional view showing a shaft through scroll compressor according to the present invention;
5 is a plan view showing a compression unit in the shaft-through scroll compressor according to FIG.
6 is a longitudinal sectional view showing a compression unit according to FIG. 4;
7 and 8 are a state diagram of the force distribution shown from the front and the top view showing the relationship between the back pressure and the gas force in the compression section of the shaft-through scroll compressor according to FIG.
9 and 10 are experimental graphs showing the stability of the shaft-through scroll compressor according to the present invention compared with the conventional shaft-through scroll compressor,
11 and 12 are longitudinal sectional views showing another example of the shaft-through scroll compressor according to the present invention.

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

Figure 4 is a longitudinal sectional view showing a axial through scroll compressor according to the present invention, Figure 5 is a plan view showing a compression unit in the axial through scroll compressor according to Figure 3, Figure 6 is a longitudinal sectional view showing a compression section according to Figure 4, Figure 7 and 8 are a state diagram of the force distribution shown in the front and the top view showing the relationship between the back pressure and the gas force in the compression section of the shaft-through scroll compressor according to FIG.

As shown therein, in the shaft-through scroll compressor according to the present embodiment, the driving motor 20 is installed inside the sealed container 10, and the main frame 30 and the sub side of each of the upper and lower sides of the driving motor 20 are respectively. Frame 40 is installed, the fixed scroll 50 is fixedly installed on the upper side of the main frame 30, between the fixed scroll 50 and the main frame 30 is engaged with the fixed scroll 50 and the drive motor A rotating scroll 60 may be installed to be coupled to the rotating shaft 23 of the 20 to compress the refrigerant while the rotating motion is performed.

The airtight container 10 may be formed of a cylindrical casing 11 and an upper shell 12 and a lower shell 13 which are welded to cover the upper and lower portions of the casing 11, respectively. The suction pipe 14 may be installed on the side of the casing 10, and the discharge pipe 15 may be installed on the upper shell 12. The lower shell 13 also functions as an oil chamber for storing oil supplied so that the compressor can operate smoothly.

The drive motor 20 may include a stator 22 fixed to the inner surface of the casing 10, and a rotor 22 positioned inside the stator 22 and rotated by interaction with the stator 22. have. In the center of the rotor 22, a rotating shaft 23 that rotates with the rotor 22 may be coupled.

An oil passage F is formed in the center of the rotating shaft 23 along the longitudinal direction of the rotating shaft 23, and an oil for supplying the oil stored in the lower shell 13 to the upper end of the rotating shaft 23. Pump 24 may be installed. The pin portion 23c may be eccentrically formed at the upper end of the rotation shaft 23.

The main frame 30 is fixed to the outer peripheral surface of the casing 11 or between the casing 11 and the upper shell 12, or fixed by welding together with the casing 11 and the upper shell 12. Can be. And the center of the main frame 30 is formed with a bearing hole 31 for radially supporting the rotating shaft 23, the periphery of the bearing hole 31 in the annular shape so that the first sealing member 71 to be described later is inserted The first sealing groove 32 may be formed.

The first sealing member 71 may be formed in a simple shape, such as a rectangular cross section or a circular cross section, but may be formed in a shape of a cross section of a recess in which one side is opened and the other side is blocked. In this case, the first sealing member 71 forms an outer surface such that the opened surface faces the back pressure chamber S3 between the main frame 30 and the turning scroll 60, while the blocked surface has the bearing hole 31. It may be preferable that the opening surface of the first sealing member 71 is further opened by the refrigerant in the back pressure chamber S3 so as to further increase the sealing force.

As shown in FIG. 7, the first sealing member (or the first sealing groove) 71 may be installed so that its geometric center CL4 substantially coincides with the center of the rotation shaft (ie, the center of the bearing hole) CL2. have.

The fixed scroll 50 may be fixed by pressing the outer peripheral surface of the casing 11 and the upper shell 12 in a shrink fit manner, or may be joined by welding together with the casing 11 and the upper shell 12. . In addition, the bottom surface of the hard plate portion 51 of the fixed scroll 50 is engaged with the turning wrap 62 to be described later, and the first compression chamber S1 is provided on the outer surface of the turning wrap 62, and the second compression chamber is provided on the inner surface. Fixing wraps 52 respectively forming S2 may be formed.

The revolving scroll 60 may be engaged with the fixed scroll 50 and supported on the upper surface of the main frame 30. Swivel scroll 60 is a circular plate portion 61 is formed in a substantially circular shape, two pairs of compression chambers (S1) (S2) that are continuously engaged with the fixed wrap 52 on the upper surface of the hard plate portion 61 (S2) Swivel wrap 62 may be formed to form. In addition, a substantially circular rotary shaft coupling part 63 may be formed at a central portion of the hard plate part 61 to which the pin part 23c of the rotary shaft 23 is rotatably inserted and coupled.

The pin portion 23c of the rotary shaft 23 is inserted into the rotary shaft coupling portion 63 through the hard plate portion 61 of the turning scroll 60, and the turning wrap 62, the fixed wrap 52, and the pin portion 23c are inserted therein. May be installed to overlap the radial direction of the compressor. Here, in the compression, the repulsive force of the refrigerant is applied to the fixed wrap 52 and the swing wrap 62, and a compression force is applied between the rotation shaft coupling portion 63 and the pin portion 23c as a reaction force thereto. As described above, when the pin portion 23c of the rotating shaft 23 penetrates through the hard plate portion 61 of the turning scroll 60 and overlaps with the wrap in the radial direction, the repulsive force and the compressive force of the refrigerant are based on the hard plate portion 61. Are added to the same side and can be offset against each other.

On the other hand, the fixed wrap 52 and the swing wrap 62 may be formed in an involute curve, but in some cases may be formed to have a curve other than the involute curve. Referring to FIG. 5, when the center of the rotating shaft coupling part 63 is referred to as O and the two contact points are respectively P1 and P2, the two contact points P1 and P2 are connected to the center O of the rotating shaft coupling part. It can be seen that the angle α defined by the two straight lines is smaller than 360 ° and the distance l between the normal vectors at each contact point is also larger than zero. Accordingly, the compression ratio can be increased since the first compression chamber S1 immediately before the discharge has a smaller volume than the case where the fixed wrap 52 and the swing wrap 62 formed of the involute curve are provided.

In addition, a protruding portion 53 protruding toward the rotation shaft coupling portion 63 is formed near the inner end of the fixed wrap 52, and the protruding portion 53 has a contact portion 53a protruding from the protruding portion 53. Can be further formed. Accordingly, the inner end of the fixing wrap may be formed to have a larger thickness than other portions.

The rotating shaft coupling portion 63 may be formed with a recess 64 to be engaged with the protrusion 53. One side wall of the concave portion 64 may be in contact with the contact portion 53a of the protrusion 53 to form one side contact point P1 of the first compression chamber S1.

Meanwhile, the second sealing groove 65 may be formed in an annular shape on the bottom surface of the hard plate portion 61 of the turning scroll 60 so that the second sealing member 72 to be described later is inserted.

The second sealing member 72 may be formed in a simple shape, such as a rectangular cross section or a circular cross section, but may be formed in the shape of a cross section of a cylinder having one side open and the other side blocked as shown in FIG. 6. In this case, the second sealing member 72 forms an inner surface such that the opened surface faces the back pressure chamber S3, while the second sealing member 72 is formed in an annular shape forming an outer surface so that the blocked surface faces the outer circumferential surface of the turning scroll 60. This may be preferable because the sealing surface of the second sealing member 72 is opened by the refrigerant in the back pressure chamber S3, so that the sealing force can be further increased.

As shown in FIG. 7, the second sealing member (or the second groove) may have its geometric center CL5 eccentrically formed from the center CL2 of the rotation shaft toward the discharge port 54.

For example, in the case of the shaft through scroll compressor, the distribution of gas force formed in the compression chamber is biased toward the discharge port 54 on the right side of the drawing from the center CL6 of the rotating shaft coupling portion as shown in FIG. 7. The back pressure distribution formed at S3 may also be formed at a position where the geometric center CL5 of the second sealing member 72 is substantially coincident with or close to the center CL6 of the rotation shaft coupling part so that the distribution of the back pressure may also correspond to the distribution of the gas force. Or as shown in FIG. 8, the moment arm, which is the distance t2 between the gas force action point P4 in the compression chamber and the back pressure action point P3 in the back pressure chamber S3, is smaller than the turning radius, more precisely. It may be desirable to be formed at a position that will be approximately 1/2 or less.

Reference numeral 66 in the figure denotes a back pressure hole.

In the shaft-through scroll compressor according to the present embodiment as described above, when the rotating shaft 23 rotates by applying power to the driving motor 20, the rotating scroll 60 eccentrically coupled to the rotating shaft 23 generates a constant trajectory. In accordance with the swing movement, the first compression chamber (S1) and the second compression chamber (S2) formed between the swing scroll 60 and the fixed scroll (50) continuously move to the center of the swing movement, respectively, the volume decreases. Thus, a series of processes of discharging while repeating suction compression of the refrigerant are repeated.

Here, between the first sealing member 71 inserted into the first sealing groove 32 of the main frame 30 and the second sealing member 72 inserted into the second sealing groove 65 of the turning scroll 60. The back pressure chamber S3 is formed, and the pivoting scroll 60 is supported in the axial direction by the back pressure of the back pressure chamber S3, so that the turning wrap 62 and the fixed wrap 52 are opposite to each other of the hard plate portion 51. ), The axial direction of the compression chamber (S1) (S2) is sealed.

However, in the case of the shaft-through scroll compressor, as the rotary shaft coupling portion 63 is formed at the center of the turning scroll 60, the gas force distribution of the compression chamber is equal to the radius of the rotary shaft coupling portion 63 at the shaft center CL3. The turning radius and the eccentricity of the eccentric bush (unsigned) inserted into the pin portion are eccentrically formed to the right. Accordingly, when both the first sealing member 71 and the second sealing member 72 are installed in the main frame 30, the back pressure action point P3 of the back pressure chamber S3 is far from the gas force action point P4. The moment arm is lengthened, which may cause the swing scroll to become unstable.

In view of this, in the present embodiment, as shown in Figs. 7 and 8, as the operating point P4 of the gas force of the compression chamber is eccentrically formed on the right side of the drawing, the operating point P3 of the back pressure is also moved to the right side so that the gas It is possible to improve the compression efficiency by reducing the axial leakage and friction loss by reducing the axial scroll and the loss of friction by reducing the distance (t2), that is, the moment arm with the action point (P4) of the force.

FIG. 9 is a graph showing the degree of stability when both the first sealing member 71 and the second sealing member 72 are installed in the main frame 30 in the shaft scroll scroll compressor, and FIG. When the first sealing member 71 is installed in the main frame 30, the second sealing member 72 in the revolving scroll 60 is a graph showing the degree of stability. Here, the stability of the turning scroll is a dimensionless number indicating the degree of stability of the turning scroll, and it can be said that the stability index is smaller than 1 in the operation map of the compressor indicating the appropriate operating range of the compressor.

In the case of FIG. 9, when both the first sealing member 71 and the second sealing member 72 are installed in the main frame 30, a part of the driving map is included in an area showing instability, that is, in an area having stability of 1 or more. It can be seen that the swing scroll behavior becomes unstable. On the other hand, when the first sealing member 71 is installed on the main frame 30, and the second sealing member 72 is installed on the swing scroll 60, the acting point P3 of the back pressure is the acting point P4 of the gas force. It can be seen that the distance t2 between the two operating points, i.e., the moment arm length, is smaller than the turning radius and the stability index of all the driving maps becomes 1 or less.

On the other hand, if there is another embodiment of the scroll compressor according to the present invention.

That is, in the above-described embodiment, the main frame and the fixed scroll are independently provided so that the turning scroll is positioned between the main frame and the fixed scroll, but the present embodiment is a fixed scroll 150 in which the main frame is integrated as shown in FIG. ) Is formed, the rotating scroll 160 is coupled to the upper surface of the fixed scroll 150, the upper frame 130 is provided on the upper surface of the rotating scroll 160 to support the rotating scroll 160.

In this case, the first sealing member 171 and the second sealing member 172 forming the back pressure chamber S3 may be installed between the upper surface of the turning scroll 160 and the bottom surface of the upper frame 130. As the pivot discharge outlet 167 is formed in the swing scroll 160 and the fixed discharge outlet 135 is formed in the upper frame 130, the first sealing member 171 is rotated in the upper frame 130. The second sealing member 172 may be installed at 160.

The first sealing member 171 is fixedly installed around the fixed side discharge port 135, while the second sealing member 172 is the working point P4 of the gas force and the working point P3 of the back pressure as in the above-described embodiment. The moment arm between) may be installed at a position shorter than the length of the turning radius, more precisely 1/2 or less. In the figure, reference numeral 164, which is not described, denotes a turning discharge port, and 165, a back pressure hole.

Accordingly, since the basic configuration and the effect are similar to those of the above-described embodiment, a detailed description thereof will be omitted. In this case, however, the position of the fixed side discharge port 135 may be appropriately changed in consideration of the working point P3 of the back pressure without being formed to coincide with the center of the upper frame 130, that is, the shaft center. The distance between the action point P4 and the action point P3 of the back pressure is made significantly smaller than the turning radius so that the gap between the geometric center CL4 of the first sealing member and the geometric center CL5 of the second sealing member is narrow. The turning scroll 160 can be further stabilized.

On the other hand, when the pivoting scroll 260 is supported on the upper surface of the fixed scroll 250, the main frame is integrated as described above and the upper frame 230 is installed on the rear surface of the pivoting scroll 260 fixed side discharge port 235 ) Can be changed to an appropriate position, and as shown in FIG. 12, both the first sealing member 271 and the second sealing member 272 may be provided on the rear surface of the turning scroll 260. In this case, since the geometric center CL4 of the first sealing member and the geometric center CL5 of the second sealing member coincide with each other, the moment arm due to the pivoting motion of the swinging scroll 260 is eliminated, thereby causing the rotation of the swinging scroll 260. The behavior can be more stable. 264 is a turning side discharge port, and 265 is a back pressure hole.

30: main frame 32: the first sealing groove
50: fixed scroll 52: fixed wrap
54 discharge port 60: turning scroll
62: turning wrap 63: rotating shaft coupling portion
65: second sealing groove 66: back pressure hole
71: first sealing member 72: second sealing member
S3: Back pressure chamber CL1: Kinematic center of back pressure chamber
CL2: center of rotation shaft CL3: center of compression chamber pressure
CL4: Kinematic center of the first sealing member CL5: Kinematic center of the second sealing member
CL6: center of rotation shaft coupling part

Claims

Airtight containers;
A fixed scroll fixed to the sealed container and having a fixed wrap formed thereon;
A turning scroll having a turning wrap engaged with the fixed wrap to form a compression chamber, and a rotating shaft engaging portion coupled to the eccentric portion of the rotating shaft so as to overlap laterally with the turning wrap and pivoting with respect to the fixed scroll;
A frame installed on a rear surface of the swing scroll; And
And a plurality of sealing members installed at regular intervals in a lateral direction between the rear surface of the pivoting scroll and the frame to form a back pressure chamber.
The first sealing member installed inside of the plurality of sealing members is coupled to the frame, while the second sealing member installed outside is coupled to the pivoting scroll.
A bearing hole is formed in the frame so that the rotating shaft passes therethrough.
The second sealing member is provided eccentrically with respect to the center of the bearing hole as the turning radius of the turning scroll,
And a spacing between a back pressure working point of the back pressure chamber and a gas force working point of the compression chamber is smaller than a turning radius of the turning scroll.

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The method of claim 1,
The frame is provided with a discharge port so that the refrigerant discharged from the compression chamber is discharged to the sealed container,
And the second sealing member is provided eccentrically with respect to the center of the discharge port by the turning radius of the turning scroll.

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The method of claim 1,
And the second sealing member is provided such that a distance between a back pressure working point of the back pressure chamber and a gas force working point of the compression chamber is 1/2 or less of a turning radius of the turning scroll.

The method according to any one of claims 1, 3 and 5,
The inner space of the sealed container is divided into a drive unit including a drive motor and a high pressure compression unit,
The driving unit is coupled to the rotating shaft to drive the rotating compressor.

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