JPH0427793A - Compressor - Google Patents

Abstract

PURPOSE:To improve abrasive state in the sliding part of a shaft and a bearing even if in such a severe condition as using the refrigerant 1,1,1,2 tetrafluoroethane, by applying polyimide containing MoS2 or polyamideimide resin on a shaft surface as coating. CONSTITUTION:A shaft 14 and a main bearing 8, a sub bearing 9 are formed of cast iron in a compressor 1. Polyimide containing 1-50weight% of MoS2 or polyamideimide resin is applied with thickness of 1-30mum on the entire surface of the shaft 14 as coating. Thus, a decrease in the abrasion amount can be attempted because MoS2, solid body lubricant, elevates the initial adaptability of the sliding parts between the shaft 14 and the bearings 8, 9.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a compressor used in freezing and refrigerating equipment, air conditioners, and the like.

Conventional Technology In recent years, refrigerants such as difluorodichloromethane (hereinafter referred to as R12) and difluorochloromethane (hereinafter referred to as R22), which contain chlorine in the molecule, have been conventionally used in refrigerators and refrigerators and air conditioners due to environmental problems such as the destruction of the ozone layer. ) etc., to a refrigerant 1.1.1.2 tetrafluoroethane (hereinafter referred to as R134a) that does not contain chlorine in the molecule is being considered.

However, the refrigerant R134a, which does not contain chlorine in its molecules,
The lubrication performance is poor and it is necessary to improve the characteristics of the sliding material of the compressor.

An example of a conventional compressor will be described below with reference to the drawings.

FIG. 3 shows a cross-sectional view of a conventional compressor, and FIG. 4 shows a cross-sectional view of a mechanical part of the conventional compressor. In FIG. 3, 1 is a compressor. 2 is a sealed shell, 3 is a stator that is shrink-fitted to the sealed shell 2, 4 is a rotor that forms a motor with the stator 3, and 5 is a shaft that is shrink-fitted to the rotor 4. Further, 6 is a roller incorporated in the eccentric part of the shaft 5, 7 is a cylinder that houses the roller 6, 8 is a main bearing of the shaft 6, 9 is a sub-bearing of the shaft 5, and 10 is press-fitted into the sub-bearing 9 and sealed. This is the suction pipe welded to the shell 2.

FIG. 4 is a cross-sectional view taken along the line AA in FIG. Next, the operation will be explained again.

The shaft 6 is rotated by the motor composed of the stator 3 and the rotor 4, and the roller 6 is rotated eccentrically, so that the refrigerant Ganu R12 introduced into the cylinder 7 through the suction pipe 10 is Compressed. In addition, as the shaft 5 rotates, the lubricating oil (
(naphthenic mineral oil) 11 passes through the oil absorption pipe 12 to the shaft 6
゜Secondary bearing 9. It is supplied to the main bearing 8, and then to the entire machine part through the clearances of each part. Here, the shaft 5 and the main bearing 8. The secondary bearing 9 is made of cast iron (JIS: Fe1
2), and the shaft 6 was further treated with leulite to improve its initial conformability.

Problems to be Solved by the Invention However, the above configuration was conceived on the premise that the conventional refrigerants R12 and R22, which have high lubrication performance, are dissolved in the lubricating oil of the compressor. If refrigerant R134a is used, which does not contain refrigerant and has poor lubricity, the shaft and bearing parts will wear out and sufficient durability cannot be maintained.

Therefore, a compressor specification that satisfies the characteristics when using refrigerant R134a, which has poor lubrication performance, has been desired.

In view of the above problems, the present invention improves the durability of a compressor using refrigerant R134a by optimizing the sliding material.

Means for Solving the Problems In order to solve the above problems, the compressor of the present invention has a shaft surface coated with polyamideimide or polyimide resin containing 1 to 60% by weight of molybdenum disulfide to a thickness of 1 to 30 Am. It is.

Function: With the above-described structure, the present invention uses molybdenum disulfide, which is a solid lubricant, to improve the initial conformability of the sliding parts on the shaft surface, thereby reducing the amount of wear and improving the durability of the compressor. It is something that improves.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

FIG. 1 shows a sectional view of the compressor of the present invention. FIG. 2 shows a cross-sectional view of the mechanical part of the compressor of the present invention.

In FIG. 1, 1 is a compressor. 2 is a sealed shell;
3 is a stator that is shrink-fitted to the sealed shell 2; 4 is a rotor that forms a motor with the stator 3; and 14 is a rotor 4.
The shaft is shrink-fitted to the

Further, 6 is a roller incorporated in the eccentric part of the shaft 14;
7 is a cylinder housing the roller 6, 8 is a main bearing of the shaft 14, 9 is a sub-bearing of the shaft 14, and 1o is a suction pipe press-fitted into the sub-bearing 9 and welded to the sealed shell 2.

FIG. 2 is a sectional view taken along the line AA in FIG. 1, and shows that the vane 13 is housed in the groove of the cylinder 7, and its tip is in sliding contact with the outer circumference of the roller e. Next, its operation will be explained. The motor composed of the stator 3 and rotor 4 rotates the shaft 14, and the roller 6 rotates eccentrically, thereby compressing the refrigerant gas R134a introduced into the cylinder T through the suction pipe 10. be done. Also, as the shaft 14 rotates, the lubricating oil (polypropylene glycol) 16 at the bottom of the sealed shell 2 passes through the oil absorption pipe 12 due to the pumping effect of the spiral groove 14a formed on the outer periphery of the shaft surface, and the shaft 14° Bearing9. It is supplied to the main bearing 8, and further supplied to the entire machine part through the clearances of each part. Here, the shaft 14 and the main bearing 8. The secondary bearing 9 is made of cast iron (JIS: Fe12), and the entire surface of the shaft 14 is coated with a polyimide resin containing 16% by weight of molybdenum disulfide (hereinafter referred to as MoS 2) to a thickness of 8 to 12 μm. ing.

The coating layer applied to the shaft 14 has excellent abrasion resistance, good conformability, and does not abrade the mating material.
In particular, initial wear is reduced in the sliding parts between the shaft 14, the main bearing 8, and the sub-bearing 9, and as a result, durability is improved by reducing wear. Further, the reason why the coating is applied to the shaft 14 is that coating, spraying, etc. are easy, and by automating the coating, the accuracy of the film thickness is increased and correction of the shaft diameter by post-processing is unnecessary. When coating the inner surface of a bearing, a difference in film thickness tends to occur near the end face and near the center, and dimensions need to be adjusted in post-processing. Due to the deformation, the inner diameter of the bearing must be reworked.

In order to confirm the effect of improving durability with the above configuration, a 6-month continuous operation test of the compressor was conducted to evaluate the amount of wear on the shaft, main bearing, and sub-bearing (hereinafter, the main bearing and sub-bearing are collectively referred to as bearings). The results are shown in the attached table. Here, Comparative Examples 1 to 3 show specifications in which the shaft is coated with a resin coating containing graphite or polytetrafluoroethylene (hereinafter referred to as PTFE) and electroless nickel plating. The material specifications of the conventional compressor are shown as Comparative Example 4.5.

(↓・Sue F I 1, white) Comparative Example 5 is a case where conventional refrigerant R12 and lubricating oil (mineral oil) were used. The results show that the wear of the through hole, shaft, and bearing is less than 1 μm, and υ is hardly worn and durability can be ensured.

On the other hand, when refrigerant R134a, which does not contain chlorine in its molecules, is used, polypropylene glycol is used as the lubricating oil to ensure solubility with the refrigerant. The amount of wear exceeds 2 to eμm so that it can be determined. In general, it is said that polypropylene glycol, which is a synthetic oil, has better properties than mineral oil, so the lubricity of refrigerant R134a, which does not contain chlorine in its molecules, is higher than that of conventional refrigerant R1.
This shows that adhesion has occurred on a part of the sliding surface, making the sliding condition unstable. Therefore, durability is significantly reduced.

Further, in Comparative Examples 1 to 3, the shafts were subjected to a surface treatment selected on the assumption that the shafts were easy to manufacture and did not require post-processing, similar to the present example, but each had its own problems. In Comparative Example 1, the entire shaft surface was coated with a polyimide resin containing 15% by weight of graphite to a thickness of 8 to 10 μm, but as shown in the attached table, the coating film itself had poor wear resistance, resulting in wear of 5 to 10 μm. occurs and durability cannot be maintained. In Comparative Example 2, 10% of PTFE was applied to the entire shaft surface.
It is coated with polyimide resin containing % by weight to a thickness of 6 to 10 μm, and as shown in the attached table, wear on the inner surface of the bearing, which is the mating material, is suppressed, and the sliding surface is also smooth and smooth. The wear type of the shaft is 2 to 7 μm, and the wear resistance of the coating film is slightly inferior. This is because, although PTFE has excellent sliding properties, the wear resistance deteriorates because υPTFE swells and softens due to the refrigerant R134a and the lubricating oil polypropylene glycol.

Therefore, durability is insufficient. In Comparative Example 3, electroless nickel plating was applied to the entire shaft surface to a thickness of 10 to 1
The surface hardness was adjusted to Hv 400-450 after aging for 30'c x 2 hours.As shown in the attached table, the wear resistance of the shaft itself has improved and almost no wear is seen. Abrasion of the inner surface of the bearing, which is the mating material, increases and durability deteriorates. In this case, it may be possible to improve the characteristics by applying similar plating to the inner surface of the bearing of the mating material, but this would be disadvantageous in terms of man-hours and cost.

On the other hand, in this example, the entire surface of the cylinder was coated with a polyimide resin containing 15% by weight of M o S 2 to a thickness of 8 to 12 μm, and even when refrigerant R134a and polypropylene glycol lubricating oil were used, there was almost no wear and sufficient wear was achieved. Durability can be maintained. This is Mo S 2
Due to the lubricating effect of MoS 2, the initial familiarization between the shaft and bearing progresses rapidly, suppressing wear and microscopic adhesion, and MoS 2 itself and the polyimide resin that holds MoS 2 have excellent chemical resistance and It is believed that because of its excellent solvent resistance, the film itself was able to maintain its wear resistance without deteriorating its properties even in an atmosphere of refrigerant 134a and polypropylene glycol lubricating oil, which have a strong swelling effect.

As described above, in this embodiment, the compressed gas is cooled [R1
34a and using polypropylene glycol as the lubricating oil, the bearing is made of cast iron, the shaft is made of cast iron, and then coated with polyimide resin containing 16% by weight of MoS2. It was found that sufficient durability could be maintained with almost no wear.

In this example, the shaft and the bearing are made of cast iron, but it is believed that the same effect can be obtained without much difference in wear resistance even if the shaft material is made of steel and the bearing material is made of iron-based sintered material. Further, the resin used to coat the shaft is preferably polyimide or polyamide-imide resin as it has excellent chemical resistance and solvent resistance, and the thickness of the coating is preferably 91 to 308 m in terms of effectiveness and economy. Further, the proportion of MoS2 blended in the resin is preferably 1 to 5% by weight. If it is less than 1% by weight, the lubricating effect will not be sufficiently exhibited, and the
If it exceeds % by weight, the strength of the resin layer may decrease and problems such as peeling may occur.

Effects of the Invention As described above, according to this embodiment, M o
By coating with polyimide or polyamideimide resin containing S2, the wear condition of the sliding parts of the shaft and bearing can be improved even under severe conditions using refrigerant 1134a, which has poor lubricity and strong swelling action, and improves the durability of the compressor. You can maintain your sexuality.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a compressor according to an embodiment of the present invention, Figure 2 is a partial sectional view of Figure 1, Figure 3 is a sectional view of a conventional compressor, and Figure 4 is a portion of Figure 3. FIG. 8...Main bearing, 9...Sub bearing, 14.
·····shaft. Name of agent: Patent attorney Shigetaka Awano and 1 other person Main bearing diagram

Claims (1)

[Claims] The gas to be compressed is refrigerant 1,1,1,2 tetrafluoroethane, and the components of the compressor include a shaft, a roller attached to an eccentric portion of the shaft, a cylinder housing the roller, and a groove in the cylinder. a vane that is housed in a vane and whose tip portion slides on the outer periphery of the roller; and a bearing that supports the shaft; the bearing is made of cast iron or an iron-based sintered material, and the shaft is made of cast iron or A compressor made of steel whose shaft surface is coated with polyamideimide or polyimide resin containing 1 to 50% by weight of molybdenum disulfide to a thickness of 1 to 30 μm.