JPS59188090A - Rotating sleeve for rotary compressor - Google Patents

Abstract

PURPOSE:To make improvements in lubrication capacity, by making up a rotating sleeve to be supported rotatably inside a housing with a ferrous material, while forming a soft nitriding layer on the outer circumferential surface and embedding a solid lubricant in a concave part around graphite of the said layer. CONSTITUTION:A rotary compressor houses a rotating sleeve 6 rotatably inside a cylindrical housing 3 and eccentrically sets up a rotor 8 in which plural vanes 12 are slidably set up in a radial direction inside the sleeve, while an empty space between the rotating sleeve 6 and the rotor 8 is partitioned into plural working chambers. In this case, the rotating sleeve 6 is formed with a ferrous material, for example, flake graphite cast iron, and soft nitriding treatment is performed on both inner and outer circumferential surfaces 6a and 6b, forming a soft nitriding layer 17 on them. And, a mixture 21 mixing epoxy resin with a solid lubricant is embedded in a concave part around graphite 19 to be exposed by polishing treatment.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to improvements in rotary sleeves for rotary compressors.

(Prior art) Various types of rotary compressors such as air pumps have been put into practical use, and a rotary sleeve is provided inside a cylindrical housing. A type of rotary compressor is also well known in which the outer end surfaces of a plurality of vanes supported by the rotor are brought into contact with the inner circumferential surface of the rotary sleeve by centrifugal force, thereby rotating the rotary sleeve together with the rotor.

This type of rotary compressor has the advantage that the rotating sleeve and vanes rotate at almost the same speed, reducing the sliding resistance of the vanes, allowing engines to operate in a wide range of rotations from low to high rotations. The rotating sleeve has recently been attracting attention as being ideal for turbochargers such as the The sleeve is eccentric with respect to the housing, and the outer circumferential surface of the rotating sleeve is pressed against the inner circumferential surface of the housing, creating large sliding resistance, which causes wear and seizure of the rotating sleeve.
Furthermore, a problem arises in that the driving torque of the rotary compressor increases. This problem becomes particularly important when the rotating sleeve is supported without lubrication.

By the way, in Japanese Patent Application No. 57-112350, the present applicant has proposed improving the wear resistance of a carbon vane that is lightweight and has excellent adhesion to a mating material (for example, a rotating sleeve) in a rotary compressor. In order to reduce the driving torque, the rotating sleeve is made of iron-based material, a nitrocarburized layer is formed on the inner and outer circumferential surfaces, and the outer circumferential surface is machined to reduce the inner and outer circumferential surfaces. We have already proposed a method in which the surface roughness between the surface and the surface is changed.

(Purpose of the Invention) The present invention is a further development of the application of the applicant's previous application, and is based on the present invention. A recess is formed between the crystallized graphite, and we focused on the fact that this recess causes sliding resistance between the rotating sleeve and the housing, scratch wear on the vane, and rust due to moisture. By utilizing the solid lubricant in the concave portion, the present invention aims to provide a rotary compressor with enhanced lubricity for the housing and vanes of the rotary sleeve.

(Structure of the Invention) Therefore, the present invention provides a rotary compressor of the above type equipped with a rotary sleeve, in which the rotary sleeve is formed of an iron-based material, and a soft nitrided layer formed by soft nitriding on at least the outer peripheral surface of the rotary sleeve. is formed, and a solid lubricant is embedded in the recesses around the graphite exposed on the outer surface of the nitrocarburized layer.

That is, the present invention aims to improve the strength and wear resistance by nitrocarburizing at least the outer peripheral surface of a rotating sleeve made of a ferrous material, and further embeds a solid lubricant in the recesses around the graphite in the nitrocarburizing layer. This is intended to reduce the sliding resistance of the rotating sleeve with respect to the housing, to further improve wear resistance, and to reduce the driving torque of the rotary compressor.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In FIGS. 1 and 2, the rotary compressor 2 has a casing having a rotational pressure composition 1, and side housings 4.4 are attached to both sides of a cylindrical center housing 3 by bolts and nuts 5.

Reference numeral 6 denotes a reversible rotary sleeve rotatably provided within the casing 2, the outer diameter of which is slightly smaller than that of the cylindrical center housing 3; The air blown out from the side shown in the figure forms an air layer 7 between the inner circumferential surface 3a of the cylindrical center housing 3 and the outer circumferential surface 6b of the rotating sleeve 6, and rotates the rotating sleeve 6 within the casing 2. (f) In Fig. 1, the gap between the cylindrical center housing 3 and the rotating sleeve 6 is shown to be large for illustration purposes, but it is actually extremely small. ,3
It is 0 to 50μ. ] 8 is a rotor rotatably provided in the casing 2 with one axis eccentric to the axis of the rotating sleeve 6, and a shaft 83.8b protruding to both sides in the axial direction is connected to the side housing 4, On the outside of the side housing 4, a boot U 10 is mounted on the 110,000 shaft 8ai, which is supported by bearings 9.9 provided in the side housing 4. Although not specifically shown, this pulley 10 is driven by a bell I-drive by a prime mover or the like.

The rotor 8 has four grooves 11 and 11 formed at right angles to each other from its outer surface to the vicinity of the shaft center. It is slidably pushed in in the radial direction so that it can protrude toward the surface 6a.

The base 712 is rotated by the centrifugal force caused by the rotation of the rotor 8.
The outer end surface 12a of the rotary sleeve 6 is urged to protrude further, and its outer end surface 12a comes into contact with the inner circumferential surface 6al of the rotary sleeve 6, and by this contact, the space between the rotary sleeve 6 and the rotor 8 is divided into four working chambers 1. '3a.

It is divided into 13b, 13C, and 13d.

1j, 14 are embedded in the inner wall surfaces of the side housings 4, 4, and ring-shaped side seals 15, 16, which receive the thrust of the rotating sleeve 6, are respectively provided in the side housings on the side opposite to the drive side of the rotor 8. These are the inlet and outlet ports.

10,000, Fig. 3(a) (as shown, the above rotating shaft IJ
- The professional is made of iron-based material (for example, flake graphite cast iron), and the inner circumferential surface 6a and outer circumferential surface 6b of the rotating sleeve 6 are subjected to soft nitriding treatment to form soft nitrided layers 17 and (7). Further, the inner circumferential surface 6a and the outer circumferential surface 6b are polished.The thickness of the nitrocarburized layer 17.17 may be approximately 10 microns.

In this way, by nitrocarburizing the rotary sleeve 6, the strength of the single-rotation sleeve 6 is increased, and by polishing the inner circumferential surface 6λ, the sliding resistance of the carphone vane 12 is reduced, thereby preventing seizure. The polishing of the outer circumferential surface 6b makes it compatible with the inner circumferential surface 3a (hard Cr plated) of the cylindrical center housing 3.

Next, as shown in FIG. 3(a), graphite 19 is exposed on the outer circumferential surface 6b of the rotating sleeve 6 after the nitrocarburizing and polishing treatments, which causes sliding resistance. Figure 3 (
b) As shown here (here, the recess 2 around this graphite 19
0, a solid lubricant 21 is buried therein.

As the solid lubricant 21, it is preferable to use an epoxy resin having excellent heat resistance and wear resistance as a binder mixed with fluororesin powder having excellent lubricity. The mixing ratio is 100 parts by volume of epoxy resin to 100 to 120 parts of solid lubricant such as fluororesin powder.
It is preferable to set it to about 0 volume part. Heat-resistant grease may be used in place of the epoxy resin, and graphite, molybdenum disulfide, boron nitride, or the like may be used in place of the fluororesin powder.

The method of burying the solid lubricant 21 is shown in Fig. 4(a).
As shown in the figure, solid lubricant 21 is sprayed onto the outer circumferential surface 6b of the rotating sleeve 6 at an air pressure of 2 to 3/d. This spraying adjusts the coating thickness depending on the time.

Even if it is used as it is, the protruding portion will be scraped off by contact with the inner peripheral surface 3a of the first cylindrical center housing 3 as shown in FIG. 4(b), but it will not be completely removed as shown in FIG. 4(C). ? Before drying, the protruding portions may be smoothed out by pressing with the roll 22.

Thereafter, the solid moisturizing agent 21 is preferably heated and cured at 1600C to 250C for 30 minutes. ■ Menopause is common at temperatures below -60°C, and saturation occurs at temperatures above 250°C.

In this way, by embedding the solid lubricant 21 in the recess 20 around the graphite 19 of the nitrocarburized layer 7 on the outer peripheral surface 6b of the rotating shaft IJ-Pro, the inner periphery i 3 of the center housing/\ring 3 The sliding resistance with a is reduced.

A durability test was conducted on a rotary compressor equipped with the rotary sleeve 6 configured as described above. The test conditions are as follows.

■ The circular center housing 3 is made of Aj-based alloy, and the inner peripheral surface 3a is hard Cr plated to a roughness of 2μ or less after polishing.]
was applied.

(2) The rotating sleeve 6 was formed of flake graphite cast iron, subjected to gas nitrocarburizing treatment, and the inner circumferential surface 6a and outer circumferential surface 6b were polished.

(2) Details of the composition of the solid lubricant 21 are shown in Table 2.

Table 2 ■ Pump capacity used 400CC Honf rotation speed
5 (JOOrpm test darkness 1
f-1r The results of the fluctuation of the driving torque of the rotary compressor l under the above conditions are shown in Figure 5. and the outer peripheral surface 6b was simply polished (Comparative Example 2)
For △, after nitrocarburizing and polishing the outer peripheral surface 6b, the recess 20 around the graphite 19 (this solid lubricant 21
It can be seen that the driving torque is significantly lower in the case of ☆ (Example) in which the is buried.

Figure 6 shows the rotating sleeve 6 after the durability test (after IHr).
This shows the results of the calibration of the amount of wear on the outer circumferential surface 6b of the untreated one, where the amount of wear is extremely large and seizure has already occurred. The occurrence of mono-scratches is observed to be reduced to some extent. On the other hand, in the product of the present invention, the amount of wear is much lower than that of the first two, and it can be seen that the sliding resistance of the rotary sleeve against the housing is significantly reduced.

Table 4 shows test data on the drive torque and the amount of wear on the outer circumferential surface 6b of the rotating sleeve 6 due to the combination of the binder and the lubricant.

Table 4 Note that all volume parts of the lubricant are relative to the binder.

(Effects of the Invention) As is clear from the above description, the present invention provides a rotating sleeve made of an iron-based material and subjected to nitrocarburizing treatment, and recesses around the graphite exposed on the outer surface of the nitrocarburizing layer on the outer peripheral surface. Since the solid lubricant is embedded in the rotating sleeve, the strength and wear resistance of the rotating sleeve are the same as above, and the solid lubricant reduces sliding resistance and drive torque. Therefore, the infiltration of moisture and the like is prevented, and corrosion resistance is improved, and especially rust, which is a problem with iron-based materials, is effectively prevented.

Note that the present invention is not limited to applying nitrocarburizing treatment to the inner circumferential surface as well.

[Brief explanation of the drawing]

Figure 1 is a front sectional view of the rotary compressor - Figure 2 is I of Figure 1.
-I sectional view, FIG. 3(a) is an enlarged sectional view of the A section in FIG. 2 after polishing treatment, and FIG. 3(b) is an enlarged sectional view of the A section in FIG. Figure 4 (a), Figure 4 (b), Figure 4
Figure (C) is a cross-sectional view showing the procedure for spraying solid lubricant and the procedure for removing protruding parts, and Figure 5 is a graph showing the amount of variation in driving torque with and without nitrocarburizing treatment and with and without solid lubricant.
FIG. 6 is a graph showing wear on the outer circumferential surface of the rotating sleeve. DESCRIPTION OF SYMBOLS 1... Rotating compressor, 2... Casing, 3... Circular center housing, 6... Rotating sleeve, 6a
...Inner peripheral surface, 6b...Outer peripheral surface -7...Air layer, 8
... Rotor, 12... Vane, 15... Suction row 16... Discharge port, 17... Soft-nitrided layer, 19...
Graphite, 20... recess, 21... solid lubricant. Patent applicant: Toyo Kogyo Co., Ltd. Agent
People Patent Attorneys Aobai Bo and 2 others Figure 5 Figure 6 Procedural Amendment (voice) 1982! ! Director General of the Japan Patent Office on the 24th, 1998 Patent Application No. 57620, 2 Name of Invention, Rotating Sleeve of Rotary Compressor, 3 Relationship with the Person Who Amends the Case, Patent Applicant, 4, Agent] 5, Order of Z. nZ elbow (spontaneous correction) 7. Contents of correction (1) Akira, Book Ta, page 8, lines 4 to 6 “After the polishing process......, but with J. ``After polishing process, correct it to J.'' □ That's all.

Claims (1)

[Claims] (1) A cylindrical rotating sleeve rotatably provided in a cylindrical housing, a rotor rotatably provided in the housing with its axis eccentric to the rotating sleeve, and a rotor formed on the rotor. In a rotary compressor, the rotary compressor is equipped with a vane fitted in a groove, and the outer end surface of the vane is brought into contact with the rotary sleeve to divide the space between the rotor and the rotor into a plurality of working chambers. A soft nitrided layer is formed by soft nitriding treatment on at least the outer peripheral surface of the rotating sleeve, and a solid lubricant is buried in the recess around the graphite exposed on the outer surface of the soft nitrided layer. The rotating IJ-tub of the rotary compressor is characterized by: