KR20140136796A

KR20140136796A - Scroll compressor

Info

Publication number: KR20140136796A
Application number: KR1020130057317A
Authority: KR
Inventors: 김학영; 이강욱; 김철환
Original assignee: 엘지전자 주식회사
Priority date: 2013-05-21
Filing date: 2013-05-21
Publication date: 2014-12-01
Also published as: KR102033109B1

Abstract

The scroll compressor according to the present invention is characterized in that the sealing portion is provided on the bearing surface between the periphery of the rotary shaft of the orbiting scroll and the corresponding fixed scroll so that the refrigerant leaks into the bearing water hole in the compression chamber in the case of low- It is possible to prevent the refrigerant from flowing into the compression chamber from the axial water hole, thereby improving the compression efficiency of the compressor.

Description

[0001] SCROLL COMPRESSOR [0002]

The present invention relates to a scroll compressor, and more particularly to a scroll compressor in which a sealing member is provided around a final compression chamber.

The scroll compressor forms a compression chamber in which the orbiting scroll of the fixed scroll and the orbiting scroll of the orbiting scroll are engaged with each other while the orbiting scroll pivots with respect to the fixed scroll and continuously moves between the fixed lap and the orbiting lap to suck and compress the refrigerant .

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

The behavior characteristics of the scroll compressor are determined by the shape of the fixed lap and the orbiting lap. The fixed lap and the orbiting lap may have any shape, but usually have the shape of an involute curve that is easy to process. The involute curve means a curve corresponding to the locus drawn by the end of the thread when the thread wound around the base circle having an arbitrary radius is released. When the involute curve is used, the thickness of the wrap is constant and the rate of volume change becomes constant. In order to obtain a high compression ratio, the winding number of the lap is increased, but the size of the compressor also increases.

On the other hand, the orbiting scroll generally has a circular lap on one side of a hard plate having a disk shape, and a boss is formed on a rear surface where the orbiting lap is not formed, so that the orbiting scroll is connected to a rotary shaft for pivotally driving the orbiting scroll. This configuration can form the orbiting wrap almost over the entire length of the end plate, thereby making it possible to reduce the diameter of the end plate to obtain the same compression ratio. On the other hand, the reaction point for applying the repulsive force of the coolant during compression and the reaction force for canceling the repulsive force are applied So that the behavior of the orbiting scroll becomes unstable in the course of operation, so that vibration and noise are increased.

As a method for solving such a problem, a so-called axial through scroll compressor in which the point where the rotary shaft 1 and the orbiting scroll 2 are coupled is formed on the same surface as the orbiting wrap 2a as shown in Fig. In such an axial through scroll scroll compressor, since the point of action of the repulsive force of the refrigerant and the point of action of the reaction force act on the same point, the problem of the inclination of the orbiting scroll (2) can be solved.

2, the rotary shaft 1 passing through the axial water hole 3b of the fixed scroll 3 is connected to the rotary shaft coupling portion 2b of the orbiting scroll 2, A portion of the refrigerant compressed in the compression chambers S1 and S2 is located close to the compression chamber S1 and the compression chamber S1 in the high pressure portion and the water hole 3b in the low pressure portion fixed scroll 3 are positioned close to each other, Is leaked between the periphery of the rotary shaft engaging portion 2b of the orbiting scroll 2 and the end plate portion 3c of the fixed scroll 3, and the compressor efficiency is greatly reduced. Particularly, when the axial through scroll scroll compressor is installed in a cooling / heating apparatus, when the cooling operation requiring less cooling power than the heating operation is performed, the wrap expansion is relatively small and the gap between the fixed scroll (3) and the orbiting scroll The refrigerant leakage may be increased while the refrigerant is spread.

An object of the present invention is to provide a scroll compressor capable of reducing the leakage of refrigerant between a compression chamber and a bearing hole.

In order to achieve the object of the present invention, A stationary scroll fixed to the hermetically sealed container and formed with a bearing hole and a fixed lap formed around the bearing hole; A revolving scroll having a revolving lap which engages with the fixed lap and forms a first compression chamber and a second compression chamber on the outer side and the inner side, A rotary shaft having an eccentric portion at one end thereof and coupled to the rotary shaft coupling portion of the orbiting scroll through the bearing hole of the fixed scroll so that the eccentric portion overlaps laterally with the orbiting scroll; And a driving unit for driving the rotary shaft, wherein a sealing portion is provided on a bearing surface between the periphery of the rotary shaft coupling portion of the orbiting scroll and the corresponding fixed scroll.

In the scroll compressor of the present invention, since the sealing member is provided on the bottom surface of the rotary shaft coupling portion located between the compression chamber and the axial water hole, the compression efficiency of the compressor can be improved by cutting off the refrigerant to be leaked into the axial hole in the compression chamber.

1 is a longitudinal sectional view showing a compression section of a conventional axial through scroll compressor,
FIG. 2 is a longitudinal sectional view showing a refrigerant leakage in a compression chamber during a cooling operation, showing an "A" portion in the axial through scroll compressor according to FIG. 1,
FIG. 3 is a longitudinal sectional view showing a shaft-through scroll compressor according to the present invention,
FIG. 4 is a plan view of the compression section in the axial through scroll compressor according to FIG. 3,
Fig. 5 is a longitudinal sectional view showing the "B" part in the axial through scroll compressor according to Fig. 3,
Fig. 6 is a perspective view showing the orbiting scroll and the sealing member separated from each other in the compression unit according to Fig. 5,
FIG. 7 is a longitudinal sectional view showing a state in which a compression chamber and a bearing water hole are sealed in a compression unit according to FIG. 5;
FIG. 8 is a longitudinal sectional view showing another example of the sealing member in the axial through scroll compressor according to FIG. 3;
FIG. 9 is a graph showing comparison of changes in volume efficiency with and without a sealing member in the axial through scroll compressor according to FIG. 3; FIG.

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

FIG. 3 is a longitudinal sectional view showing a shaft-passing scroll compressor according to the present invention, FIG. 4 is a plan view showing a compression unit in the shaft-passing scroll compressor according to FIG. 3, Fig. 6 is a perspective view showing the orbiting scroll and the sealing member separated from each other in the compression unit according to Fig. 5, and Fig. 7 shows a state in which the compression chamber and the bearing water hole are sealed in the compression unit according to Fig. FIG.

As shown in the figure, the scroll compressor according to the present embodiment is provided with a driving motor 30 inside the sealed container 10, and a fixed scroll 30 integrally formed with the main frame on the upper side of the driving motor 20. [ The orbiting scroll (40) is installed on the upper side of the fixed scroll (30) so as to be engaged with the fixed scroll (30) and coupled to the rotary shaft (23) of the drive motor .

The hermetic container 10 may include a cylindrical casing 11 and an upper shell 12 and a lower shell 13 welded to cover the upper and lower portions of the casing 11, respectively. A suction pipe 14 may be installed at a side of the casing 10 and a discharge pipe 15 may be installed at an upper portion of the upper shell 12. The lower shell 13 also functions as an oil chamber for storing the supplied oil so that the compressor can be smoothly operated.

The driving motor 20 may include a stator 22 fixed to the inner surface of the casing 10 and a rotor 22 disposed inside the stator 22 and rotated by the interaction of the stator 22 have. A rotating shaft (23) rotating together with the rotor (22) can be coupled to the center of the rotor (22).

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

The outer peripheral surface of the fixed scroll 30 can be press-fitted and fixed between the casing 11 and the upper shell 12 in a heat shrinking manner or can be welded together with the casing 11 and the upper shell 12. [

A boss portion 32 is formed at the center of the hard plate portion 31 of the fixed scroll 30. A bearing hole 33 may be formed in the boss portion 32 such that the rotary shaft 23 passes through the boss portion 32. A first compression chamber S1 is formed on the outer surface of the orbiting wrap 42 and a second compression chamber S1 is formed on the inner surface of the orifice S2 may be formed.

The orbiting scroll (40) can be supported on the upper surface of the fixed scroll (30). The orbiting scroll 40 is formed in a substantially circular shape and has a pair of compression chambers S1 and S2 (not shown) formed on the upper surface of the rigid plate 41, The orbiting wrap 42 may be formed. A substantially circular rotary shaft engaging portion 43 may be formed at the center of the long plate portion 41 so that the pin portion 23c of the rotary shaft 23 is rotatably inserted and engaged.

The pin portion 23c of the rotary shaft 23 is inserted into the rotary shaft coupling portion 43 through the hard plate portion 31 of the fixed scroll 30 and the rotary wrap 42 and the fixed lap 34 and the pin portion 23c are inserted, May be installed so as to overlap in the radial direction of the compressor. Here, during compression, the repulsive force of the refrigerant is applied to the fixed lap 34 and the orbiting wrap 42, and a compressive force is applied between the rotary shaft engaging portion 43 and the pin portion 23c as a reaction force thereto. As described above, when the pin portion 23c of the rotary shaft 23 passes through the hard plate portion 41 of the orbiting scroll 40 and overlaps with the lap in the radial direction, the repulsive force and the compressive force of the coolant are applied to the hard plate portion 41 So that they can be offset from each other.

On the other hand, the fixed lap 34 and the orbiting lap 42 may be formed of involute curves, but in some cases, they may be formed to have curves other than involute curves. 4, when the center of the rotary shaft coupling part 43 is O and the two contact points are P1 and P2, the two contact points P1 and P2 are connected to the center O of the rotary shaft coupling part It can be seen that the angle a defined by the two straight lines is smaller than 360 degrees and the distance l between the normal vectors at each contact point also has a value greater than zero. Accordingly, the compression ratio can be increased because the first compression chamber S1 just before discharge has a smaller volume than when the first compression chamber S1 has the fixed lap 34 and the orbiting wrap 42 formed of the involute curve.

A protrusion 35 protruding toward the rotary shaft engaging portion 43 is formed in the vicinity of the inner end of the fixed lap 34. A contact portion 35a protruding from the protrusion 35 is formed in the protrusion 35 Can be formed. Accordingly, the inner end of the fixed lap can be formed to have a larger thickness than the other portions.

The rotation shaft engaging portion 43 may be formed with a recess 44 that engages with the projection 35. One side wall of the concave portion 44 may be in contact with the contact portion 35a of the projection 35 to form one contact point P1 of the first compression chamber S1.

In the drawing, reference numerals 50 and 45 denote an articulation and an upper frame, respectively.

The scroll compressor according to the present embodiment as described above is configured such that when the rotary shaft 23 rotates by applying power to the driving motor 20, the orbiting scroll 40, eccentrically connected to the rotary shaft 23, And the compression chambers S1 and S2 formed between the orbiting scroll 40 and the fixed scroll 30 move continuously to the center of the orbiting motion and the volume is reduced to continuously suck and compress the refrigerant, This is a process of repeating a series of processes.

Here, the bottom surface of the orbiting scroll 40, that is, the bottom surface 43a around the rotary shaft engaging portion 43 and the bearing surface B on the upper surface of the hard plate portion 31 of the fixed scroll 30 come into contact with each other, S1) and the second compression chamber (S2). However, in the first compression chamber S1 and the second compression chamber S2, the volume of the first compression chamber S1 and the second compression chamber S2 becomes narrower toward the inner side, The volume of the concave portion 44 of the orbiting scroll 35 and the orbiting wrap 42 becomes sharply sharply and the pressure of the compression chamber rises suddenly.

Accordingly, in the case of the axial through scroll scroll compressor, since the shaft hole 33 forming the relatively low pressure is arranged close to the first compression chamber S1 and the second compression chamber S2, A part of the refrigerant compressed in the second compression chamber (S2) can leak into the axial hole (33) by the pressure difference. However, when the sealing portion 100 is formed between the compression chambers S1 and S2 and the shaft water hole 33 as in the present embodiment, the refrigerant in the compression chambers S1 and S2, which are high- Leakage to the hole 33 can be effectively blocked.

As shown in FIGS. 5 and 6, the bottom surface of the rotary shaft coupling portion 43, that is, the annular sealing groove 110 is formed on the bearing surface so as to surround the rotary shaft coupling portion 43 around the rotary shaft coupling portion 43 And a sealing member 120, which is also annular, may be inserted into the sealing groove 110.

The sealing member 120 may be formed in a cross sectional shape with one side opened and the other side closed as shown in FIG. In this case, the sealing member 120 is formed into an annular shape whose inner surface forms a closed surface facing the shaft hole 33 while the opened surface forms an outer surface facing the compression chambers S1 and S2 The opening surface of the sealing member 120 is opened by the refrigerant to be leaked in the compression chambers S1 and S2 so that the sealing force can be further increased.

8, the sealing member 120 may be formed in a simple shape such as a rectangular cross section or a circular cross section. The refrigerant to be leaked into the compression chambers S1 and S2 is introduced into the sealing groove 110 and the sealing member 120 is brought into close contact with the inner surface of the sealing groove 110, It is possible to prevent the refrigerant from leaking out by being brought into close contact with the surface (B).

FIG. 9 is a graph showing changes in volumetric efficiency with and without a sealing member in the axial through scroll compressor according to FIG. 3; FIG. As shown in the figure, when the sealing portion is provided between the compression chamber and the pouring water hole, the volume efficiency is improved by about 1 to 3% in each of the experimental examples.

In this way, a part of the refrigerant compressed in the compression chamber moves gradually inward toward the discharge port of the orbiting-side discharge port so as to be compressed and leaked to the bearing hole as a relatively low-pressure portion. However, a sealing member is provided on the bottom surface of the rotary- It is possible to prevent the refrigerant from leaking from the compression chamber to the shaft hole, thereby preventing the compression efficiency from being lowered. Particularly, in the case where a scroll compressor is installed in the air conditioning / air-conditioning unit, since the amount of cooling power required is low during the cooling operation, the expansion of the refrigerant leaks due to the expansion of the space between the rotary shaft- Even in this case, the sealing member blocks the gap between the orbiting scroll and the fixed scroll, thereby greatly reducing the refrigerant leakage.

In the meantime, although the low-pressure compressor in which the internal space of the hermetically sealed container forms the low-pressure portion has been described, the internal space of the hermetically sealed container can be equally applied to the high-pressure compressor constituting the high-pressure portion. The basic configuration and operation effects according to the present embodiment are similar to those of the above-described embodiment, and thus a detailed description thereof will be omitted.

In this case, however, it is preferable to arrange the opening surface of the sealing member so as to face the bearing hole which is the high-pressure portion because the sealing effect can be enhanced.

30: fixed scroll 33: bearing water hole
34: stationary lap 40: orbiting scroll
42: orbiting wrap 43:
43a: bottom surface of the rotary shaft coupling portion 100:
110: sealing groove 120: sealing member

Claims

Airtight container;
A stationary scroll fixed to the hermetically sealed container and formed with a bearing hole and a fixed lap formed around the bearing hole;
A revolving scroll having a revolving lap which engages with the fixed lap and forms a first compression chamber and a second compression chamber on the outer side and the inner side,
A rotary shaft having an eccentric portion at one end thereof and coupled to the rotary shaft coupling portion of the orbiting scroll through the bearing hole of the fixed scroll so that the eccentric portion overlaps laterally with the orbiting scroll; And
And a driving unit for driving the rotating shaft,
Wherein a sealing portion is provided on a bearing surface between the periphery of the rotary shaft coupling portion of the orbiting scroll and the corresponding fixed scroll.

The method according to claim 1,
Wherein a sealing groove is formed on a bearing surface of the rotary shaft coupling portion so as to surround the rotary shaft coupling portion.

3. The method of claim 2,
And a sealing member having an annular shape is inserted into the sealing groove.

The method of claim 3,
Wherein the sealing member is formed in a cross sectional shape with one lateral side opened and the other side closed, and the opening face of the sealing member is installed so as to face the high pressure side.

5. The method according to any one of claims 1 to 4,
The internal space of the closed container is divided into a low-pressure portion and a high-pressure portion by the fixed scroll,
And the drive unit is installed in the low-pressure portion.