JP3783182B2 - Tip seal for compressor, compressor using the tip seal, and surface treatment method for tip seal for compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a scroll compressor and a surface treatment method for a tip seal provided on a spiral wrap constituting a fixed scroll or a swing scroll provided in the compressor.
[0002]
[Prior art]
As is well known, in the scroll compressor, the spiral wrap of the fixed scroll and the spiral wrap of the orbiting scroll are positioned alternately to form a plurality of compression chambers. When the orbiting scroll is swung in this state, the compression chambers move from the spiral outer periphery to the center to reduce the volume, thereby compressing the gas. At this time, the spiral side surface of the swing scroll wrap slides on the bottom of the fixed scroll. Similarly, the spiral side of the fixed scroll wrap also slides on the bottom of the orbiting scroll.
[0003]
In order to maintain the airtightness of these sliding portions, a tip seal is attached to each lap. Conventionally, a resin chip seal reinforced with glass fiber or the like in a Teflon-based resin or a flat strip steel chip seal made of high Cr alloy steel is used for this chip seal.
[0004]
[Problems to be solved by the invention]
However, the conventional tip seal is inferior in wear resistance, and particularly when the scroll compressor is used for compressing refrigerant gas, particularly when using HFC or HCFC refrigerant as the refrigerant gas, the wear resistance is particularly low. Was a problem.
[0005]
The present invention has been made to solve the above-described problems, and provides a surface treatment method for a tip seal having excellent wear resistance, a tip seal having excellent wear resistance, and a compression using such a tip seal. The purpose is to provide a machine.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the first invention is provided by being fitted into a slit-like groove formed on one side of a spiral wrap constituting a fixed scroll or an orbiting scroll and protruding from the groove. The chip seal is made by plasma nitriding a high Cr alloy steel flat strip steel with a Cr content of 12 to 15% by weight to form only a nitrogen diffusion layer, thereby increasing the hardness of the base metal and increasing its wear resistance. This is a tip seal for a compressor, characterized by using a flat strip steel tip seal with improved resistance.
[0008]
The second invention is a compressor using an HFC refrigerant or HCFC refrigerant as a refrigerant and using the compressor chip seal according to the first invention.
[0009]
According to a third aspect of the present invention, the amount of Cr provided to protrude from the groove fitted into a slit-like groove formed on one side of a spiral wrap constituting a part of the fixed scroll or the orbiting scroll is 12 to 15 weights. % Of the high-strength steel plate strip steel chip seal,
Temperature is 400-550 ° C
Gas ratio of H ₂ gas / NH ₃ gas is 70-80% by volume / 20-30% by volume
A chip for a compressor characterized in that only a nitrogen diffusion layer is formed by plasma nitriding under a condition of a processing time of about 3 to 10 hours, thereby increasing the hardness and improving the wear resistance of the base material. It is a surface treatment method of a seal.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 3, the whole longitudinal cross-sectional view of the scroll compressor 1 which concerns on this embodiment is shown.
That is, an electric element and a scroll compression element driven by the electric element are accommodated in the sealed container 3. The electric element includes a stator 5 fixed around the inside of the hermetic container 3 and a rotor 7 disposed at a central portion of the stator 5 with a predetermined gap. A rotating shaft 9 disposed in the axial direction of the hermetic container 3 is coupled to the central portion of the rotor 7 in a penetrating state, and one end side of the rotating shaft 9 is the center of the support frame 11 that supports the scroll compression element. It is penetrated by the part and supported rotatably.
[0011]
A crank portion 13 is formed eccentrically with respect to the axis of the rotary shaft 9 at the end portion of the rotary shaft 9 penetrating the support frame 11, and an orbiting scroll 15 is connected to the crank portion 13.
[0012]
The orbiting scroll 15 includes a boss hole 17 connected to the crank portion 13 at the center of one side surface of a disc-shaped end plate, and a spiral wrap 19 formed on the other side surface of the end plate. It has.
[0013]
A fixed scroll 21 is coupled to the support frame 11. A wrap 23 is formed on the fixed scroll 21, and a plurality of compression chambers 25 are formed on the lap 19 of the swing scroll 15 in a staggered state.
[0014]
A refrigerant gas suction pipe 27 penetrating the sealed container 3 is connected to the side wall surface of the fixed scroll 21. A discharge port 29 for discharging the compressed refrigerant gas into the sealed container 3 is provided at the center of the fixed scroll 21. A discharge pipe 30 for discharging the refrigerant gas discharged into the hermetic container 3 to the outside of the hermetic container 3 is provided at the end of the hermetic container 3. In addition, the arrow in a figure shows the flow of refrigerant gas.
[0015]
When the rotary shaft 9 rotates, the lap 19 of the orbiting scroll 15 swings and swings, and as shown in FIG. 2, the plurality of compression chambers A, B, C, D, and E are sequentially moved from the outer peripheral side to the center side. The volume gradually decreases and the refrigerant gas is compressed. At this time, the side surface of the spiral wrap 23 of the fixed scroll 21 slides on the bottom surface of the swing scroll 15, that is, the end plate. Similarly, the side surface of the spiral wrap 19 of the orbiting scroll 15 slides on the bottom of the fixed scroll 21. In order to maintain the airtightness of these sliding portions, chip seals are attached to the laps 19 and 23.
[0016]
In FIG. 1, the attachment state of this chip seal is shown.
A slit-like groove 31 is formed on one side of the spiral wrap 19 (23), and a band-like chip seal 33 is fitted into the groove 31. The band-shaped widthwise end of the chip seal 33 that is fitted slightly protrudes from the groove 31 and slides to the bottom of the mating member (15, 21) when swiveling and swinging to maintain airtightness. To do.
[0017]
In this embodiment, the tip seal 33 is made of high Cr alloy steel, the Cr amount is 12 to 15% by weight, the C amount is 0.6 to 0.8% by weight, and the balance is Fe. Further, plasma nitriding treatment was performed under the following conditions. That is,
The temperature is 400-550 ° C,
The gas ratio of H ₂ gas / NH ₃ gas constituting the atmosphere is
70-80% by volume / 20-30% by volume,
The processing time was about 3 to 10 hours. By plasma nitriding under these conditions, it was possible to form only a nitrogen diffusion layer of 20 to 50 μm without causing precipitation of a compound (ε-phase) that is normally harmful to the function of a chip seal. The diffusion layer has a hardness of about Hv550 made of high Cr alloy steel as a base material, whereas the hardness is increased to about Hv1200, and it has been found that the diffusion layer is sufficiently hardened. This can greatly improve the wear resistance.
[0018]
(Example)
The components of the flat strip steel made of high Cr alloy steel to be subjected to the plasma nitriding treatment are 0.6 to 0.7% by weight for C, 0.35% by weight maximum for Si, and 0.6 to 0.00% for Mn. 8 wt%, P is 0.03 wt% at maximum, S is 0.02 wt% at maximum, and Cr is 12.5 to 13.5 wt%. Hardness before processing was Hv550-650.
[0019]
And it heated gradually over 1 hour and reached to predetermined temperature (450-550 degreeC). The next 1 hour was exposed to an atmosphere of 100% H ₂ gas as a pretreatment. Further, it was exposed to a predetermined mixed gas atmosphere of hydrogen and ammonia for about 3 to 10 hours. That is, the gas ratio of H ₂ gas / NH ₃ gas is 70 to 80% by volume / 20 to 30% by volume.
[0020]
After the treatment, it was confirmed by experiments that the wear resistance was improved. That is, as a result of continuous wear test for 1000 hours, when the treatment was not performed, the thickness decrease due to the wear was 110 μm, whereas the treatment was 20 μm.
[0021]
【The invention's effect】
As described above, according to the first invention, and the hardness up subjected to plasma nitriding wear resistance excellent flat plate steel strip tip seal, to provide a particularly flat steel strip tip seal made of Cr alloy steel In addition, according to the second invention, it is possible to provide an excellent HFC or HCFC refrigerant compressor.
[0022]
Further, according to the third invention, the gas ratio of H ₂ gas / NH ₃ gas is 70 to 80% by volume / 20 to 30% by volume, so that the surface of the chip seal can be used as a chip seal. It can be cured without precipitating functionally harmful compounds (ε-phase), and the wear resistance can be improved. And, by setting the processing temperature to 400 to 550 ° C. and the processing time to about 3 to 10 hours, only a diffusion layer free from harmful compounds can be formed and cured sufficiently, and the wear resistance can be greatly improved. It could be confirmed.
[Brief description of the drawings]
FIG. 1A is a perspective view of a wrap provided in a scroll compressor according to an embodiment of the present invention, and FIG.
2 is a plan view for explaining compression of refrigerant gas by a compression chamber formed by a fixed scroll and a swing scroll having the wrap of FIG. 1. FIG.
3 is an overall longitudinal sectional view of a scroll compressor that performs compression as shown in FIG. 2;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Scroll compressor 15 Swing scroll 19, 23 Lap 21 Fixed scroll 31 Groove 33 Chip seal

Claims (3)

A base material having a Cr amount of 12 to 15% by weight is fitted on a slit-like groove formed on one side of a spiral wrap constituting a fixed scroll or an orbiting scroll and provided protruding from the groove. A high-strength steel strip made of high-Cr alloy steel is plasma-nitrided to form only a nitrogen diffusion layer , using a flat-plate strip tip seal that is harder and harder than the base metal. Compressor tip seal. The compressor using the tip seal for compressors according to claim 1 while using HFC system refrigerant and HCFC system refrigerant as a refrigerant . A high amount of the base material having a Cr amount of 12 to 15% by weight fitted into a slit-like groove formed on one side of a spiral wrap constituting a part of the fixed scroll or the orbiting scroll and protruding from the groove. Cr alloy steel flat strip steel chip seal,
Temperature is 400-550 ° C
The gas ratio of H ₂ gas / NH ₃ gas is 70 to 80% by volume / 20 to 30% by volume.
A chip for a compressor characterized in that only a nitrogen diffusion layer is formed by plasma nitriding treatment under conditions of a treatment time of about 3 to 10 hours, thereby increasing the hardness and improving the wear resistance of the base material. Seal surface treatment method.

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