JP3205234B2 - Scroll compressor - Google Patents

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 suitable for use in an air conditioner, a refrigerator, etc., which improves efficiency and reliability by simple means. It is.

[0002]

2. Description of the Related Art A conventional scroll compressor will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view of a general scroll compressor, and FIG. 4 is a sectional view of a conventional wrap meshing portion between a fixed scroll and an orbiting scroll. In the general scroll compressor shown in FIG. 1, a compression mechanism 2 and an electric motor 10 are housed in a closed case 1. The compression mechanism unit 2 has a spiral wrap on each base plate, and the fixed scroll 3 and the orbiting scroll 4 that form the compression chamber 5 by meshing with each wrap inside, and the rotation of the electric motor 10. A frame 7 having a crankshaft 6 for transmitting a force to revolve the orbiting scroll 4 and a main bearing 9 for rotating the crankshaft 6
And an Oldham ring 8 related to the rotation preventing means of the orbiting scroll 4.

The fixed scroll 3 has a spiral wrap 3b standing upright on an end plate 3a, and the orbiting scroll 4 has a spiral wrap 4b standing upright on an end plate 4a. The compression chamber 5 is formed by engaging the wrap inward. A suction pipe connected to an external cycle is press-fitted into a suction port 16 of the fixed scroll 3. The electric motor 10 includes a stator 11 and a rotor 12. The stator 11 is fixed to the sealed case 1 by shrink fitting or the like, and the rotor 12 is fixed to the crankshaft 6 by press fitting or the like.

[0004] This will be described in more detail. The outer periphery of the frame 7 is fixed to the closed case 1 and has a main bearing 9 for receiving rotation of the crankshaft 6. An orbiting scroll 4 is rotatably mounted on the eccentric portion 6a of the crankshaft 6, and an Oldham ring 8 is slidably disposed in a groove provided in the frame 7 and a groove provided in the orbiting scroll 4. 4 is prevented from rotating. Fixed scroll 3 meshing with orbiting scroll 4 to form compression chamber 5
Are fastened to the frame 7 by bolts 13. A shaft end of the crankshaft 6 opposite to the eccentric portion 6a is supported by a sub bearing 14, and the sub bearing 14 is attached to a support plate 15 fixed to the closed case 1.

The refrigerant gas sucked into the compression chamber 5 from the suction port 16 gradually decreases in volume due to the swinging motion of the orbiting scroll 4 and moves toward the center.
c. There are always a plurality of compression chambers 5. The fixed scroll 3 has a release valve 17 for releasing pressure when the pressure in the compression chamber is excessively compressed, or a discharge valve,
Some include a pressure control valve such as a check valve 18.
19 is a discharge pipe connected to the external cycle.

In general, the gap between the end plate 4a of the orbiting scroll 4 and the tip of the wrap 3b of the fixed scroll 3, the gap between the end plate 3a of the fixed scroll 3 and the tip of the wrap 4b of the orbiting scroll 4, and the turning When the gap between the wrap 4b of the scroll 4 and the wrap 3b of the fixed scroll 3 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 compressor input increases. When the leakage of the refrigerant gas reaches the suction port 16, not only the input increases but also the refrigeration capacity decreases. Therefore, if the gap is reduced, the performance of the compressor is improved. On the other hand, if the gap is not properly managed, the performance of the compressor is reduced.

[0007] However, during operation of the compressor, the compression chamber 5
Gas pressure acts on the discharge mechanism,
Since the suction pressure acts, the orbiting scroll 4 and the fixed scroll 3 are deformed by these forces. The deformation is generally more remarkable in the orbiting scroll 4 than in the fixed scroll 3. This is because the end plate 3a of the fixed scroll 3 is thicker and more rigid than the end plate 4a of the orbiting scroll 4. Therefore, if the gap is not reduced in a state where the deformation occurs during operation, the performance is 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 machining accuracy so that there is no gap between the orbiting scroll 4 and the fixed scroll 3. Yes, 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 process the scroll so that there is no gap in consideration of the deformation.

As a countermeasure against this problem, a surface treatment that is relatively easily worn on both or one of the orbiting scroll 4 and the fixed scroll 3 is performed so that the surface treatment layer 23 fills the gap with the counterpart member. And a method for reducing leakage. Examples of this are disclosed in, for example, JP-A-54-157315 and JP-A-57-4900.
No. 1, JP-A-57-99202, JP-A-57-99202
No. 570002.

In the technique described in Japanese Patent Application Laid-Open No. 54-157315, the entire surface or a part of the wrap and the end plate is formed of a familiar and easily wearable material, and the lower layer is a hardened layer. Specific examples of the easily wearable substance include iron sulfide and ethylene tetrafluoride resin. In the technique described in Japanese Patent Application Laid-Open No. 57-49001, the whole or part of the surface of the wrap portion and the end plate portion is formed of an elastic film, and the lower layer is made of a rigid material. As a specific example of the film of the elastic body, a fluorine resin is exemplified.

Further, the technique described in Japanese Patent Application Laid-Open No. 57-99202 discloses a technique in which a surface treatment layer is provided on the surface of at least one of the wrap portion and the end plate portion of the orbiting scroll and the fixed scroll. , Sulfurization and nitriding are exemplified. Also, Japanese Patent Application Laid-Open No. 58-5
The technique described in Japanese Patent Application Laid-Open No. 7002 discloses a technique in which a part or the surface of a head plate portion and the tip of a lap are induction hardened, and then subjected to a chemical conversion treatment (lubrite treatment).

[0012]

In the structure of the above-mentioned conventional scroll compressor, there are factors which deteriorate the performance as described below. That is, in the process of performing the surface treatment, the residual stress generated during the processing is released, and the wrap and the end plate of the scroll are deformed. Since these surface-treated layers are easily abraded, their surface is not generally removed after the surface treatment, and this deformation directly leads to an increase in the gap. Therefore, the effect of reducing the gap by the surface treatment layer is not sufficiently exhibited.

The processing stress is generated by pressing a cutting tool or a grindstone during cutting or grinding, and remains as a residual stress on a workpiece. When the surface treatment is performed, these stresses are released. Specifically, in the case of nitriding surface treatment, since the treatment temperature rises to about 570 ° C., the temperature reaches the stress release temperature and deformation occurs. In the case of chemical conversion treatment represented by manganese phosphate treatment, the treatment temperature is 9
Although it is a low temperature of 0 ° C. to 100 ° C. and there is almost no stress release when looking only at the temperature, when growing the chemical conversion treatment layer,
Since the gap between the particles acts as a minute crack, the residual stress is released and deformation occurs. In addition, the stress is released even when the resin-based material is baked.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and fully exerts the effect of surface treatment for reducing a gap, and handles orbiting scrolls, fixed scrolls from wraps and end plates. A first object is to provide a high-performance scroll compressor with reduced gas leakage.

When a pressure control valve is used for a fixed scroll, the following problem occurs when a surface treatment layer is formed on a sliding portion of the pressure control valve. First, the thickness of the surface treatment layer varies greatly and hinders sliding of the valve. Second, the leakage of the handling gas may increase due to the rough surface roughness of the surface treatment layer. Therefore, a second object of the present invention is to provide a scroll compressor in which the sliding portion of the pressure control valve is not subjected to manganese phosphate treatment and the sliding characteristics of the pressure control valve are good. is there.

[0016]

In order to achieve the first object, a scroll compressor according to the present invention comprises an electric motor and a compression mechanism connected to the electric motor in a closed container. The compression mechanism section has a spiral wrap on each end plate, and the fixed scroll and the orbiting scroll forming a compression chamber by meshing each wrap, and preventing the orbiting scroll from rotating. An Oldham ring as a means, a crankshaft for transmitting the rotational force of the electric motor to rotate the orbiting scroll, and a frame provided with a bearing for rotating the crankshaft, wherein the scroll compressor is fixed to the orbiting scroll. Both scrolls are treated with manganese phosphate and the thickness of the treated layer is larger on the orbiting scroll side than on the fixed scroll side. Further, in the above-described configuration, the objective can be easily achieved by setting the thickness of the manganese phosphate treatment layer of the orbiting scroll and the fixed scroll to 5 μm or more.

The operation of the above technical means is as follows. First, the adopted surface treatment method will be described.
The manganese phosphate treatment (lubrite treatment) has the least degree of release of residual stress as compared with nitriding treatment such as sulphiditriding treatment or baking treatment of resinous material, and can reduce deformation after treatment. The generated manganese phosphate treatment layer is soft and is suitable as a material that is easily worn by operation and reduces gaps.

Next, regarding the deformation, the orbiting scroll is larger than the fixed scroll and the orbiting scroll when the deformation due to the residual processing stress during the surface treatment is compared between the fixed scroll and the orbiting scroll.
This is because the orbiting scroll has a smaller shape and lower rigidity. The deformation occurs in the form of warpage of the entire orbiting scroll, and the end plate is deformed into a concave shape or a convex shape. Whether the shape is concave or convex depends on the processing method and chucking method, and depends on the direction in which the tensile stress and the compressive stress are generated. This deformation causes the wrap to deform in the opening direction or the closing direction.

When the vehicle is operated in such a deformed state, the leading end of the wrap of the orbiting scroll comes into contact with the mating member at the end (edge) of the leading end of the wrap of the fixed scroll. Therefore, the surface treatment layer at the end (edge) of the wrap of the orbiting scroll wears faster than any of the wrap portions of the orbiting scroll and the fixed scroll, and the base material appears earlier. Since the base material is hardly worn by the surface treatment layer, the wear is almost stopped from the time when the base material is exposed, and the action of reducing the gap also stops at that time.

Therefore, if the manganese phosphate treatment layer of the orbiting scroll is made thicker than the fixed scroll, the wrap end can be further worn out and the gap can be further reduced. Generally, the thickness of a manganese phosphate treatment used in a hermetic compressor is about 1 to 5 μm as represented by a crankshaft. However, when adopting this surface treatment as an effect of reducing the gap between the orbiting scroll and the fixed scroll, it is important to increase the thickness of the treatment, and by providing a film thickness of 5 μm or more, the above effect can be further improved. Increase.

Next, in order to achieve the second object,
The configuration of the scroll compressor according to the present invention is such that a motor and a compression mechanism connected to the motor are housed in a closed container, and the compression mechanism has a spiral shape on each end plate. A fixed scroll and orbiting scroll having wraps and engaging the respective wraps to form a compression chamber; an Oldham ring serving as rotation preventing means for the orbiting scroll; and a crank for transmitting the rotational force of the electric motor to rotate the orbiting scroll A scroll having a shaft and a frame having a bearing for rotating the crankshaft, wherein the fixed scroll is provided with a discharge port for discharging compressed refrigerant gas and a valve for controlling the pressure in the compression chamber. The manganese phosphate treatment on both the end plates of the orbiting scroll and the fixed scroll and the spiral wrap, The thickness is assumed to have thicker orbiting scroll side of the fixed scroll side, further the sliding portion of the pressure control valve provided in the fixed scroll is obtained by so as not subjected to manganese phosphate treatment.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a longitudinal sectional view of a general scroll compressor, FIG. 2 is a sectional view of a lap engagement portion between the orbiting scroll and the fixed scroll according to the present invention, and FIG. FIG. 9 is an explanatory diagram illustrating an example of a deformation mode. The scroll compressor shown in FIG.
And the motor unit 10 are housed. The compression mechanism 2
A spiral wrap is provided on each base plate, and the compression chamber 5
Fixed scroll 3 and orbiting scroll 4 forming
And a crankshaft 6 for transmitting the rotational force of the electric motor 10 to revolve the orbiting scroll 4, a frame 7 having a main bearing 9 for rotating the crankshaft 6, and an Oldham ring according to a rotation preventing means for the orbiting scroll 4. 8 is provided.

The fixed scroll 3 has a spiral wrap 3b standing upright on an end plate 3a, and the orbiting scroll 4 has a spiral wrap 4b standing upright on an end plate 4a. The compression chamber 5 is formed by engaging the wrap inward. A suction pipe connected to an external cycle is press-fitted into a suction port 16 of the fixed scroll 3. The electric motor 10 includes a stator 11 and a rotor 12. The stator 11 is fixed to the sealed case 1 by shrink fitting or the like, and the rotor 12 is fixed to the crankshaft 6 by press fitting or the like.

This will be described in more detail. An outer peripheral portion of the frame 7 is fixed to the closed case 1 and includes a main bearing 9 that receives rotation of the crankshaft 6. An orbiting scroll 4 is rotatably mounted on the eccentric portion 6a of the crankshaft 6, and an Oldham ring 8 is slidably disposed in a groove provided in the frame 7 and a groove provided in the orbiting scroll 4. 4 is prevented from rotating. Fixed scroll 3 meshing with orbiting scroll 4 to form compression chamber 5
Are fastened to the frame 7 by bolts 13. A shaft end of the crankshaft 6 opposite to the eccentric portion 6a is supported by a sub bearing 14, and the sub bearing 14 is attached to a support plate 15 fixed to the closed case 1.

The refrigerant gas sucked into the compression chamber 5 from the suction port 16 gradually decreases in volume due to the swinging motion of the orbiting scroll 4 and moves toward the center.
c. There are always a plurality of compression chambers 5. The fixed scroll 3 has a release valve 17 for releasing pressure when the pressure in the compression chamber is excessively compressed, or a discharge valve,
Some include a pressure control valve such as a check valve 18.
19 is a discharge pipe connected to the external cycle.

Here, the material of the fixed scroll 3 and the orbiting scroll 4 is cast iron.
Manganese phosphate salt treatments 21 and 22 are applied to the surfaces of the end plates 3a and 4a and the wraps 3b and 4b. The thickness of the manganese phosphate treatment layer is such that the manganese phosphate treatment layer 22 on the orbiting scroll 4 side is thicker than the manganese phosphate treatment layer 21 on the fixed scroll 3 side. In one embodiment,
The fixed scroll 3 side is about 7 μm, while the orbiting scroll 4 side is about 11 μm.

FIG. 3 is a diagram showing an example of a deformation mode of the orbiting scroll and the fixed scroll due to the processing residual stress.
It shows the shape after manganese phosphate treatment. When driving in a deformed state as shown in FIG. 3, the tip of the wrap 4b of the orbiting scroll 4 is
b At the end (edge) from the tip, it comes into contact with the mating member. Therefore, the surface treatment layer on the end portion (edge portion) of the wrap of the orbiting scroll 4 is worn faster than any of the wrap portions of the orbiting scroll 4 and the fixed scroll 3. However, since the thickness of the manganese phosphate treatment layer 22 of the orbiting scroll 4 is thicker than that of the manganese phosphate treatment layer 21 of the fixed scroll 3, the surface treatment layer at the end (edge portion) of the wrap of the orbiting scroll 4 is not formed. Even if worn, it does not happen until the base material appears. For this reason, the processing layer is worn to reduce the gap, and gas leakage from the compression chamber 5 can be reduced.

As described above, according to the present embodiment, leakage of the compression chamber can be reduced by simple means, and a high-performance scroll compressor can be obtained. That is, even if deformation due to processing residual stress occurs during surface treatment, the gap between the scroll wrap and the end plate can be reduced, and a highly efficient compressor with less leakage can be provided.

[0029]

As described above in detail, according to the present invention, the effect of the surface treatment for reducing the gap is sufficiently exhibited, and the leakage of the handling gas from the wrap of the orbiting scroll and the fixed scroll and the end plate portion is prevented. A reduced and high-performance scroll compressor can be provided. Also, since the manganese phosphate treatment is not performed on the sliding portion of the pressure control valve, a scroll compressor having good sliding characteristics of the pressure control valve can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of the present invention and a conventional scroll compressor.

FIG. 2 is a sectional view of a lap meshing portion between the orbiting scroll and the fixed scroll according to the present invention.

FIG. 3 is an explanatory diagram showing an example of a deformation mode of the orbiting scroll and the fixed scroll due to a processing residual stress.

FIG. 4 is a cross-sectional view of a conventional wrap meshing portion between a fixed scroll and an orbiting scroll.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sealing case, 2 ... Compression mechanism part, 3 ... Fixed scroll, 4 ... Orbiting scroll, 3a, 4a ... End plate, 3b, 4
b ... lap, 3c ... discharge port, 5 ... compression chamber, 6 ... crankshaft, 7 ... frame, 8 ... Oldham ring, 9 ... main bearing, 10 ... motor part, 17 ... release valve, 18 ... check valve, 21 , 22 ... manganese phosphate treated layer.

Continuation of the front page (72) Inventor Toshiyuki Terai 800 Tomita, Ohira-cho, Ohira-machi, Shimotsuga-gun, Tochigi Prefecture (58) Investigation area (Int. Cl. ⁷ , DB name) F04C 18 / 02 311

Claims (3)

(57) [Claims] An electric motor and a compression mechanism connected to the electric motor are housed in a closed container, wherein the compression mechanism has a spiral wrap on each end plate, A fixed scroll and an orbiting scroll forming a compression chamber by meshing the wraps, an Oldham ring serving as a means for preventing rotation of the orbiting scroll, a crankshaft for transmitting the torque of the electric motor to rotate the orbiting scroll, and In a scroll compressor provided with a frame having a bearing for rotating a shaft, both the orbiting scroll and the fixed scroll are subjected to a manganese phosphate treatment, and the thickness of the treated layer is changed from the fixed scroll side to the orbiting scroll side. Scroll compressor characterized by thickening. 2. The scroll compressor according to claim 1, wherein the thickness of the manganese phosphate treatment layer of the orbiting scroll and the fixed scroll is 5 μm or more. 3. An electric motor and a compression mechanism connected to the electric motor are housed in a closed container, wherein each of the compression mechanisms has a spiral wrap on each end plate. A fixed scroll and an orbiting scroll that form a compression chamber by meshing the wraps; an Oldham ring that serves as rotation preventing means for the orbiting scroll; a crankshaft that transmits the rotational force of the electric motor to rotate the orbiting scroll; A frame provided with a bearing for rotating the compressor, wherein the fixed scroll is provided with a discharge port for discharging the compressed refrigerant gas and a valve for controlling the pressure in the compression chamber, the orbiting scroll, Manganese phosphate treatment is applied to both ends of the fixed scroll and the spiral wrap, and the thickness of the treated layer is the same as that of the fixed scroll. Ri and those thick orbiting scroll side, further the sliding portion of the pressure control valve provided in the fixed scroll scroll compressor being characterized in that so as not subjected to the manganese phosphate treatment.