JP2002089466A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stable efficient scroll compressor wherein a gas leak amount is small from an initial stage of compressor operation. SOLUTION: In this scroll compressor, one of a fixed scroll 3 and a turning scroll 4 is formed with a surface treatment layer 17 having running-in property. A thickness of the surface treatment layer 17 of a surface-treated scroll end plate face 3a, 4a is set to be thinner than a thickness of the surface treatment layer 17 of a surface-treated scroll lap tip face 3c, 4c. Thereby, a gap size 13, 14 between the scroll lap tip face 3c, 4c and the end plate face 3a, 4a facing the lap tip face 3c, 4c is small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor, and more particularly, to a scroll compressor used for a refrigerator or an air conditioner.

[0002]

2. Description of the Related Art Generally, in a scroll compressor, a gap formed between a fixed scroll 3 and an orbiting scroll 4 includes an axial gap and a radial gap. Leads to. The axial gap is the gap between the end plate (tooth root) of the orbiting scroll and the tip of the wrap of the fixed scroll, and the gap between the end plate (tooth root) of the fixed scroll and the tip of the wrap of the orbiting scroll. Is a gap between the wrap side surface of the orbiting scroll and the wrap side surface of the fixed scroll.

[0003] The principle that the scroll compressor compresses the refrigerant is as follows: the side surface of the orbiting scroll wrap, the orbiting scroll end plate,
This is because the compression chamber that compresses the refrigerant formed by the fixed scroll wrap side surface and the fixed scroll end plate gradually reduces the volume from the outside of the spiral toward the center, thereby increasing the refrigerant density. However, when these gaps exist, the refrigerant gas leaks from the high-pressure compression chamber from the center of the spiral to the low-pressure compression chamber outside. In a low-pressure compression chamber, there is a problem that the pressure increases, so that the compression work increases and the electric input increases.

In particular, during operation of the compressor, gas pressure acts on the compression chamber, and suction pressure, discharge pressure, and intermediate pressure act on the outside of the compression mechanism. The scroll and the fixed scroll are deformed by these pressures. If the gap is not small in these deformations, the performance of the compressor is reduced.

[0005] To improve the performance, it is necessary to improve the processing accuracy, but there is a limit to this processing accuracy improvement.

In order to solve this problem, one or both of the base material of the orbiting scroll and the fixed scroll is liable to wear such as iron sulfide, ethylene tetrafluoride, fluororesin or manganese phosphate film after machining. Forming a surface treatment layer (having familiarity), during operation, the fixed scroll and the orbiting scroll slide, so that the contact area is cut off, and the shape follows the rough part or undulation of the mating member, Japanese Patent Application Laid-Open No. 9-3 is to reduce the gap during operation.
No. 03276.

[0007]

In recent refrigerators and air conditioners, there has been an increasing demand for energy saving, and there is an urgent need to develop an efficient compressor. As described in the related art, the surface treatment layer is generally soft, and the surfaces of the fixed scroll and the orbiting scroll that are in contact with each other are slid by sliding, so that the surface of the mating member follows the roughness and undulation of the mating member. It is intended to realize power saving in the compression chamber by reducing the leakage loss of the compression chamber and other sealing surfaces.

However, after the compressor starts operating, it takes several hours until the surface treatment layer is worn and conformed so that the surface shape follows the surface of the mating member and gas leakage is reduced. In particular, since the surface of the mirror plate formed outside the spiral wrap has high surface accuracy, it takes time until the surface treatment layer comes into contact with the counterpart member and is cut by sliding. Unless the surface treatment layer on the end plate surface is cut, the gap size of the wrap does not become small. Therefore, there is initial refrigerant gas leakage until the surface treatment layer on the end plate surface is cut. If the leakage of the refrigerant gas is large, the input is large and the refrigeration capacity is small, so that the power consumption increases during that time, and there is a problem that it takes time until the power consumption decreases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a stable and efficient scroll compressor in which the leakage of refrigerant gas is small from the initial operation stage of the scroll compressor.

[0010]

SUMMARY OF THE INVENTION The object of the present invention is to provide a fixed scroll having a spiral wrap provided on an end plate and having a mirror surface on an outer periphery of the wrap, and a spiral wrap meshed with the fixed scroll wrap on the end plate. And a turning scroll having an end surface facing the end surface of the fixed scroll on the outer periphery of the wrap, and a surface treatment layer formed on at least one of the fixed scroll and the orbiting scroll. In this case, the thickness of the surface treatment layer on the mirror-finished surface of the scroll wrap is made smaller than the thickness of the surface treatment layer on the tip surface of the scroll wrap.

By the operation of the scroll compressor, the portion of the surface treatment layer that slides on the mating member becomes familiar (wears), the thickness decreases, and the surface that does not slide remains as it is. Further, the gap dimensions 13 and 14 are 0 to a μm after machining.
In the case of (a> 0), the thickness of the surface treatment layer on the scroll head surface is smaller than the thickness of the surface treatment layer on the tip surface of the scroll wrap in the range of b to c μm (0 <b <c). Then, the gap dimensions 13 and 14 after the surface treatment are −c to
(ab) μm, and a negative range exists. In this case, in the initial stage of operation, the wrap tip surface comes into contact with the mating member earlier than the scroll end plate surface. However, the surface treatment layer on the wrap tip surface has a small contact area with the end plate facing the surface treatment layer on the mirror plate surface. Therefore, it becomes more familiar (easier to wear) than the surface treatment layer on the mirror plate surface, and leakage of the refrigerant gas in the gap is reduced in a short time.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 3 is a longitudinal sectional view of the scroll compressor according to the present embodiment. The compression mechanism 2 and the electric motor 10 are housed in the closed container 1. The compression mechanism 2 is formed of a fixed scroll 3 having a spiral wrap 3b standing (upright) on an end plate 3a, and a revolving scroll 4 having a spiral wrap 4b standing on an end plate 4a.
When the wrap 3b and the wrap 4b mesh with each other and the orbiting scroll 4 orbits, the volume of the compression chamber 5 is gradually reduced, so that the refrigerant gas is compressed. The orbiting scroll 4 is connected to the electric motor unit 10 via the crankshaft 6, and the rotational force of the electric motor unit 10 is transmitted,
Rotation is performed by preventing rotation by a rotation preventing member such as an Oldham ring. The frame 7 has a main bearing 8 for the crankshaft 6 and a thrust surface for receiving the anti-lap surface of the orbiting scroll 4. An auxiliary bearing 9 is provided on the anti-motor side of the main bearing 8.

The refrigerant gas sucked into the compression chamber 5 from the suction port 20 is compressed by the orbiting motion of the orbiting scroll 4 while gradually reducing its volume, and is directed toward the center. Is discharged from. Some fixed scrolls 3 are provided with a pressure control valve such as a release valve 11 or a check valve 12 for releasing pressure when the pressure in the compression chamber 5 becomes excessively compressed.

As described above, the gap formed between the fixed scroll 3 and the orbiting scroll 4 includes an axial gap (gap on the wrap tip surface) and a radial gap (gap on the wrap side surface). Making the gap as small as possible leads to improved performance. A gap 1 between the end plate 4a of the orbiting scroll and the tip of the wrap 3b of the fixed scroll, which is an axial gap.
3. The gap 14 between the fixed scroll end plate 3a and the tip of the orbiting scroll wrap 4b, and the orbiting scroll wrap 4b and the fixed scroll wrap 3b, which are radial gaps.
Increases, the refrigerant gas leaks from the high-pressure compression chamber to the low-pressure compression chamber. When the high-pressure refrigerant gas leaks into the low-pressure compression chamber, the pressure in the low-pressure compression chamber increases beyond the steady pressure, so the compression work until the refrigerant gas is discharged increases, and the input of the compressor increases. I will. When the leakage of the refrigerant gas reaches not only the low-pressure compression chamber but also the suction port 20, not only does the input increase, but also the amount of refrigerant gas circulating in the refrigeration cycle (refrigerant circulation amount) decreases, so that the refrigeration capacity also decreases. Therefore, if the gap is reduced, the performance of the compressor is improved because the leakage of the refrigerant gas is reduced. Conversely, if the gap is increased, the compressor performance is reduced due to a large input and a small refrigerating capacity.

Next, the relationship between the gap and the performance will be described with reference to FIG. FIG. 2 is a view in which a surface treatment is performed on the orbiting scroll 4 on which the machining is performed. In this figure, 3
c is the wrap end surface of the fixed scroll, 4c is the wrap end surface of the orbiting scroll, 3d is the end plate surface of the fixed scroll,
4d is the end plate surface of the orbiting scroll, 13 is the gap size between the wrap end surface 4c of the orbiting scroll and the fixed scroll end plate surface 3d opposed to the wrap end surface, and 14 is the wrap end surface 3c of the fixed scroll and this wrap. The gap size between the end plate surface 4d of the orbiting scroll facing the leading end surface, 15 is the gap size between the wrap side surface of the orbiting scroll 4 and the wrap side surface of the fixed scroll 3 facing this wrap side surface, and 16 is the mirror plate surface and hatching. The applied 17 is a surface treatment layer.

The end plate 4 of the orbiting scroll which is an axial gap.
a and the tip of the fixed scroll wrap 3b, the gap between the fixed scroll end plate 3a and the tip of the orbiting scroll wrap 4b, and the radial gap between the orbiting scroll wrap 4b and the fixed scroll wrap 3b. When the gap increases, refrigerant gas leaks from the high-pressure compression chamber to the low-pressure compression chamber. At this time, since the pressure of the low-pressure compression chamber increases, the compression work increases, and the input of the compressor increases. When the leakage of the refrigerant gas reaches the suction port 20, not only the input increases but also the refrigerating capacity decreases. Therefore, if the gap is reduced, the performance of the compressor is improved. Conversely, if the gap is increased, the performance of the compressor is reduced. That is, during the operation of the compressor, the gas pressure acts on the compression chamber 5, and the discharge pressure and the suction pressure act from the outside of the compression mechanism 2.
The orbiting scroll 4 and the fixed scroll 3 are deformed by these forces. If the gap is not reduced in a state where such deformation occurs during operation, the performance will be reduced.

In order to reduce leakage from the wraps and end plates of the orbiting scroll 4 and the fixed scroll 3, it is necessary to first improve the processing accuracy and eliminate the gap between the orbiting scroll 4 and the fixed scroll 3. But this has its limitations. Further, as described above, the scroll is deformed by the gas pressure, and the gap changes depending on the operating pressure condition. Therefore, it is necessary to take the deformation into consideration so that there is no gap.

As a countermeasure against this problem, a surface treatment 17 that is relatively easily worn is applied to both or one of the orbiting scroll 4 and the fixed scroll 3 so that the surface treatment layer 17 fills a gap with a counterpart member. Wear and leakage is reduced.

That is, when the surface treatment layer 17 is formed on the base material of both or one of the orbiting scroll 4 and the fixed scroll 3, some irregularities cannot be avoided on the surface. At the initial stage of starting the scroll compressor, a gap is generated due to the contact between the unevenness of the surface treatment layer surface 17 and the mating member,
Leakage of the refrigerant gas from the high-pressure section of the compression chamber 5 to the low-pressure section increases. This gap is buried by abrasion of the surface treatment layer 17 by sliding of the scroll member, so that leakage of the refrigerant gas can be suppressed. This surface treatment layer 1
7, a manganese phosphate treatment is performed in the present embodiment. The manganese phosphate treatment is performed after the machining in the treatment liquid tank is completed.
Alternatively, it is performed by immersing the fixed scroll 3 so that a substantially uniform treatment layer is formed on the surface.

The process by which the surface treatment layer 17 is adapted will now be described. Looking at the order in which the surface treatment layer 17 of the orbiting scroll 4 comes into contact in the axial direction after the operation starts, first, the surface treatment layer 17 formed on the end surface 16 of the orbiting scroll 4 is opposed to the fixed scroll head plate. It is scraped off by sliding in contact with the surface. This allows
Since the axial distance between the base material (cast material portion) of the orbiting scroll 4 and the fixed scroll 3 is reduced, the wrap tip surface 4c of the orbiting scroll 4 and the end plate surface 3a of the fixed scroll 3 facing the wrap tip surface. And the gap size 13 and
The clearance dimension 14 between the fixed scroll tip surface 3c and the end plate surface 4a of the orbiting scroll facing this surface is reduced.

As described above, gas pressure acts on the compression chamber 5 during operation of the compressor, and discharge pressure and suction pressure act from outside the compression mechanism 2 in FIG. The orbiting scroll 4 and the fixed scroll 3 are deformed by these forces, but the gap dimensions 13 and 14 are also reduced by such deformation during operation. The surface treatment layer 1 formed on the orbiting scroll mirror surface 16 to some extent
When the chip 7 is removed, the clearance dimensions 13 and 14 become zero, and the surface treatment layer 17 formed on the wrap tip surfaces 3c and 4c is removed by sliding with the end plate surfaces 4a and 3a facing each other. . Therefore, when the gap size is originally small, the surface treatment layer 17 of the mirror plate surface 16 of the orbiting scroll 3 is only slightly removed, and the gap at the tip end surface of the orbiting scroll is eliminated. Efficient operation is possible.

However, when the clearance dimension is close to the upper limit, the clearance at the tip end surface of the wrap does not become small merely by shaving the surface treatment layer 17 on the orbiting scroll head surface 16, and the clearance is always generated even during operation. Therefore, refrigerant gas leaks frequently, resulting in performance degradation.

Further, since this mirror plate surface is formed with relatively higher precision than other portions in order to be used as a reference surface at the time of machining, the unevenness of the surface surface after the surface treatment is less than that of other portions. However, since the speed of progress of wear is slow, it takes a considerable amount of time until the gap between the tip of the wrap and the end plate becomes a sufficiently small value.

Therefore, in order to reduce the gap size, it is only necessary to increase the processing accuracy of the lap tip and the end plate and to make the upper limit of the gap size as small as possible. However, as described in the prior art, it naturally follows that. There is a limit. Even if it can be done, if you do not process in consideration of deformation during operation,
During operation, the base materials (cast materials) come into contact with each other, and conversely, the sliding loss may increase.

Therefore, as shown in FIG. 1, the surface treatment is performed so that the thickness of the surface treatment layer 17 applied to the mirror plate surface 16 of the orbiting scroll 3 is smaller than the thickness of the surface treatment layer 17 applied to the tip end surface of the wrap. Thus, for example, even if the gap dimensions 13 and 14 after machining are a μm (a> 0),
The thickness of the surface treatment layer 17 is the surface treatment layer 1 on the wrap tip surface.
If the thickness is 7 μm thinner than the thickness of 7, the gap size after the surface treatment is 1
3 and 14 are a-b μm, which can be reduced by the thickness difference b μm of the surface treatment layer 17. As a result, the operation can be performed with a small gap size from the beginning of operation, and the gap is further reduced due to the familiarity of the surface treatment layer 17, so that a stable and high-efficiency scroll compression with less refrigerant gas leakage from the initial stage compared to the conventional case. Machine can be provided.

Here, as a method of producing a difference in the thickness of the surface treatment layer 17, masking or the like is applied to only a portion of the surface treatment layer 17 where the thickness of the treatment layer is to be reduced in advance, so that the treatment film is applied. There is a method of changing, or a method of removing a part of the treatment layer to be thinned after performing the surface treatment. As a method of removing the processing layer of the portion to be thinned, after forming the processing layer, a brush made of horse hair is rotated at a high speed, and the end of the brush is pressed against the mirror surface to be removed,
It is possible to remove the surface treatment layer.

According to the above embodiment, it is possible to easily provide a scroll compressor that is stable from the initial stage of operation, has good compression efficiency, and consumes less power.

In the above embodiment, the example in which the surface treatment layer 17 is formed on the orbiting scroll 4 side has been described. However, the present invention is not limited to this, and the fixed scroll 3 is not limited to this.
Needless to say, a surface treatment layer having familiarity may be formed on the side.

[0029]

As described above in detail, according to the present invention, it is possible to provide a stable and efficient scroll compressor with little leakage of refrigerant gas from the initial operation stage of the scroll compressor.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a combination of a fixed scroll and an orbiting scroll according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a combination of a fixed scroll and an orbiting scroll having a treatment layer formed on a surface thereof.

FIG. 3 is a longitudinal sectional view of the scroll compressor according to the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Closed container, 2 ... Compression mechanism part, 3 ... Fixed scroll,
4 orbiting scroll, 3a, 4a ... end plate, 3b, 4b ...
Wrap, 3c, 4c: Wrap tip surface, 3d, 4d: End plate surface, 5: Compression chamber, 6: Crankshaft, 7: Frame, 8 ...
Main bearing, 9: sub bearing, 10: electric motor unit, 11: release valve, 12: check valve, 13: gap size between the end face of the wrap of the orbiting scroll and the end plate face of the fixed scroll facing this wrap end face , 14... The gap between the wrap tip surface of the fixed scroll and the end plate surface of the orbiting scroll facing the wrap tip surface; 15... The gap between the wrap side surface of the orbiting scroll and the wrap side surface of the fixed scroll facing this wrap side surface. Dimensions, 16: mirror surface, 17: surface treatment layer, 20
... Suction port, 30 ... Discharge port.

Continued on the front page (72) Inventor Kazutaka Watanabe 800 Futami, Tomita, Ohira-machi, Shimotsuga-gun, Tochigi Prefecture F-term in the Cooling Division, Hitachi, Ltd. (Reference) 3H039 AA03 AA04 AA12 BB15 BB28 CC02 CC03 CC05 CC08 CC36

Claims (2)

[Claims] A spiral wrap having a mirror surface on the outer periphery of the spiral wrap and a spiral wrap meshing with the fixed scroll wrap on the end plate; A revolving scroll having a mirror plate surface facing the mirror plate surface of the fixed scroll on the outer periphery of the wrap, and a surface treatment layer formed on at least one of the fixed scroll and the revolving scroll, wherein the surface treated head plate is provided. A scroll compressor wherein the thickness of the surface treatment layer on the surface is smaller than the thickness of the surface treatment layer on the tip surface of the scroll wrap. 2. The surface treatment layer on the scroll head surface after the surface treatment in order to make the thickness of the surface treatment layer on the scroll head surface smaller than the thickness of the surface treatment layer on the tip surface of the scroll wrap. A scroll compressor that has been made thinner by removing oil.