JPS6330508B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Field of Application) The present invention relates to an improvement of a rotary sleeve for a rotary compressor. (Prior Art) Conventionally, various types of rotary compressors such as air pumps have been put into practical use. A rotary sleeve is provided inside a cylindrical housing, and a rotor is mounted eccentrically with respect to the rotary sleeve. A type of rotary compressor is also well known in which the outer end surfaces of a plurality of radially supported vanes are brought into contact with the inner circumferential surface of a rotary sleeve by centrifugal force, thereby rotating the rotary sleeve together with a 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. Recently, it has been attracting attention as the best choice for superchargers such as
Since the rotating sleeve is only fluidly supported with a small gap between it and the housing, the compression pressure generated during the compression stroke causes the rotating sleeve to be eccentric with respect to the housing, causing the outer peripheral surface of the rotating sleeve to A large sliding resistance is generated when the rotary sleeve is pressed against the inner peripheral surface of the housing, causing wear and seizure of the rotary sleeve, and further problems such as an increase in the driving torque of the rotary compressor occur. This problem becomes particularly important when the rotating sleeve is supported without lubrication. By the way, in Japanese Patent Application Laid-Open No. 59-136497, the present applicant has improved the wear resistance of a carbon vane that is lightweight and has excellent adhesion to a mating material such as a rotating sleeve in a rotary compressor. In order to reduce the driving torque, the mating material of the vane is made of an Al-Si alloy, an anodized film (alumite) is formed on the mating material, and the Si particles exposed on the surface of the anodized film are removed. We have already proposed a method for removing Si by removing Si. (Object of the Invention) The present invention applies the technology of the applicant's earlier application to a rotary sleeve of a rotary compressor having a rotary sleeve, and further reduces the wear of carbon vanes. It is an object of the present invention to provide a rotary sleeve for a rotary compressor that can significantly reduce the sliding resistance of the rotary sleeve, thereby reducing driving torque and preventing seizure. That is, the present invention aims to improve strength and prevent thermal deformation by applying an anodic oxide coating to the inner and outer peripheral surfaces of the rotating sleeve made of an Al-Si alloy, and by polishing and finishing the anodic oxide coating of the rotating sleeve, primary crystals are removed. There is a risk that Si particles will be exposed on the outer circumferential surface and fall off due to shocks caused by contact with the inner circumferential surface of the housing, causing abnormal wear between the inner circumferential surface of the housing and the outer circumferential surface of the rotating sleeve. In order to prevent this, an attempt was made to remove Si particles through a Si removal process, and then bury a solid lubricant in the recesses after removing the Si particles to reduce sliding resistance, improve wear resistance, and reduce drive torque. It is something to do. (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
The rotating sleeve is made of an Al-Si alloy, and an anodic oxide film is formed on the inner and outer peripheral surfaces of the rotating sleeve, and Si particles exposed on the anodic oxide film surface of at least the outer peripheral surface of the rotating sleeve are treated to remove Si. The solid lubricant is removed by the recess, and the solid lubricant is buried in the recess. (Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In FIGS. 1 and 2, 1 is a rotary compressor;
Reference numeral 2 denotes a casing of the rotary compressor 1, in which side housings 4, 4 are attached to both sides of a cylindrical center housing 3 with bolts and nuts 5. Reference numeral 6 denotes a cylindrical rotating sleeve made of Al-Si alloy that is rotatably provided in the casing 2. The outer diameter is slightly smaller than that of the cylindrical center housing 3, and the rotating sleeve 6 is bored at an appropriate position. An air layer 7 is formed between the inner circumferential surface 3a of the cylindrical center housing 3 and the outer circumferential surface 6b of the rotary sleeve 6 by the air ejected from the ejection holes (not shown), and the rotary sleeve 6 is closed to the casing. 2, it is rotatably supported without lubrication. (In addition, in FIG. 1, the cylindrical center housing 3 and the rotating sleeve 6
Although the gap is shown to be large for illustration purposes, it is actually extremely small, 30 to 50μ. ) 8 is a rotor rotatably provided in the casing 2 with its axis eccentric to the axis of the rotating sleeve 6, and a shaft 8 protruding to both sides in the axial direction.
a, 8b are supported by bearings 9, 9 provided on the side housings 4, 4, and a pulley 10 is attached to one shaft 8a on the outside of the side housing 4. Although not specifically illustrated, this pulley 10 is driven by a belt by a prime mover or the like. The rotor 8 has four grooves 11, . It is slidably inserted in the radial direction so as to protrude toward the inner circumferential surface 6a. The vane 12 is urged in the direction of protruding from the groove 11 by the centrifugal force generated by the rotation of the rotor 8, and its outer end surface 12a is brought into contact with the inner peripheral surface 6a of the rotary sleeve 6, and this contact causes the rotary sleeve to close. 6
The space between the rotor 8 and the rotor 8 is divided into four working chambers 13a,
It is designed to be divided into 13b, 13c, and 13d. In addition, 14 is a ring-shaped side seal embedded in the inner wall surface of the side housings 4, 4 and receives the thrust of the rotating sleeve 6, and 15, 16 is a suction provided in the side housing on the opposite side from the drive side of the rotor 8. The mouth is the outlet. On the other hand, as shown in FIG. 3a, the rotating sleeve 6 made of an Al-Si alloy is anodized (anodized), and its inner peripheral surface 6a and outer peripheral surface 6b are coated with an anodized coating ( alumite) 17,
form 17. The thickness of the anodic oxide films 17, 17 is preferably about 100 to 300 μm. By subjecting the rotating sleeve 6 to alumite treatment in this way, the strength of the rotating sleeve 6 is improved and thermal deformation, particularly local deformation, is prevented. Outer peripheral surface 6 of rotating sleeve 6 after alumite treatment
By the polishing process b, the Si particles 19 are exposed on the outer peripheral surface 6b (the surface of the anodic oxide film 17). These Si particles 19 are removed by a Si removal process which will be described below. The Si removal process consists of a physical process by polishing and a chemical process to elute Si particles 19. If the Si content in the Al-Si alloy is high, most of the Si particles are removed by the polishing process. removed. In chemical treatment, Si is removed using, for example, a hydrofluoric acid aqueous solution. In this case, it is better to use a relatively dilute hydrofluoric acid aqueous solution, and for Al-Si alloys containing 19% Si, treat with a 10% hydrofluoric acid aqueous solution for about 10 seconds and with a 5% aqueous solution for about 40 seconds. Si can be removed by Moreover, a mixed aqueous solution of hydrofluoric acid and nitric acid can be used. Next, Si particles 19 are placed on the outer peripheral surface 6b (the surface of the anodic oxide film 17) of the rotating sleeve 6 that has been subjected to the Si-free treatment.
After this is removed, a recess (bore) 20 remains, and a solid lubricant 18 is buried in this recess 20, as shown in FIG. 3b. As the solid lubricant 18, 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 blending ratio is preferably about 10 to 120 parts by volume of solid lubricant such as fluororesin powder to 100 parts by volume of epoxy resin. A thermosetting heat-resistant resin or heat-resistant grease may be used instead of the epoxy resin, and graphite, molybdenum disulfide, boron nitride, etc. may be used instead of the fluororesin powder. The fourth method for burying the solid lubricant 18 is
As shown in Figure a, the outer peripheral surface 6b of the rotating sleeve 6
A solid lubricant 18 is sprayed onto the surface of the anodic oxide film 17 at an air pressure of 2 to 3 kg/cm ² . Adjust the coating thickness with this spraying time. Even if it is used as is, contact with the inner circumferential surface 3a of the first cylindrical center housing 3 will result in a failure as shown in Fig. 4b.
Although the protruding portions are scraped off as shown in FIG. 4c, the protruding portions may be smoothed out by pressing with a roll 21 before it is completely dry. After that, solid lubricant 18 is heated at 160℃~250℃, 30~
It is preferable to heat and cure for 60 minutes. Below 160℃, there is a lot of wear, and above 250℃, it becomes saturated, and the rotating sleeve 6 or the anodic oxide coating 1
7 may have an adverse effect. In this way, the recesses 20 remaining in the anodic oxide film 17 on the outer circumferential surface 6b of the rotating sleeve 6 after the Si removal treatment are removed.

【table】 Details of the composition of the solid lubricant 18 are shown in Table 2.

[Table] Pump capacity used: 400c.c. Pump rotation speed: 5000rpm Test time: 10Hr Figure 5 shows the results of fluctuations in the driving torque of the rotary compressor 1 under the above conditions. The meaning of the marks is shown in Table 3.
It is as follows.

【table】

[Table] As is clear from FIG. 5, first, the drive torque of the product with alumite treatment is lower than that of the product without alumite treatment, both at the initial stage and after 10 hours. Next, those with alumite treatment, which have been subjected to Si removal treatment and then buried solid lubricant in the recesses formed by the Si removal, are those which have simply been subjected to Si removal treatment (solid lubricant The driving torque is significantly reduced compared to the case with (no agent), and the increase in driving torque between the initial stage and after 10 hours is also very small. Fig. 6 shows the results of the amount of wear on the outer peripheral surface 6b of the rotating sleeve 6 after the durability test (after 10 hours). Further, even if a solid lubricant is applied, seizure occurs due to thermal deformation of the rotating sleeve 6. In addition, even if anodized products are simply treated to remove Si, seizure will not occur, but the amount of wear is large, and in particular, many scratches occur due to the removal of Si. It is believed that the edges of the recesses formed by processing are largely responsible for wear and sticking. In this respect, in the product in which a solid lubricant was embedded after the Si-removal treatment (product of the present invention), the amount of wear was overwhelmingly reduced, and the effect of embedding the solid lubricant was obvious. Furthermore, Fig. 7 shows the results of the amount of wear on the outer end surface 12a of the carbon vane 12 after the durability test (after 10 hours), and similarly shows the results of the combination with the alumite treatment (○) and the solid lubricant (○). It can be seen that wear is significantly reduced even when the vane 12a is made of carbon. This is because reducing the sliding resistance of the rotating sleeve 6 also works advantageously to reduce the amount of wear on the carbon vane 12. Table 4 shows test data on the driving torque and the amount of wear on the outer circumferential surface 6b of the rotating sleeve 6 based on the combination of the binder and lubricant used as solid lubricants.

[Table] Note that all lubricant volume parts are based on the binder. (Effect of the invention) As is clear from the above explanation, the present invention has the following effects:
An anodic oxide film is formed on the rotating sleeve, the Si particles exposed on the surface of the anodic oxide film are removed by a deSi treatment, and a solid lubricant is buried in the recesses, so there are no Si particles on the outer peripheral surface of the rotating sleeve. Since the solid lubricant is not exposed and is buried in the recess after Si particles are removed, it prevents abnormal wear, reduces sliding resistance, improves wear resistance, and reduces driving torque. Summer. In the above embodiment, only the outer peripheral surface was treated to remove Si, but the inner peripheral surface of the rotating sleeve may also be buried with a solid lubricant after the Si removal treatment.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view of the rotary compressor, Fig. 2 is a - sectional view of Fig. 1, Fig. 3 a is an enlarged sectional view of part A in Fig. 2 after polishing, and Fig. 3 b is a solid state. FIG. 2 is an enlarged cross-sectional view of part A after burying the lubricant; FIGS.
The figure is a graph showing the amount of variation in drive torque depending on the presence or absence of alumite treatment and the presence or absence of solid lubricant. Figure 6 is a graph showing the amount of wear on the outer circumferential surface of the rotating sleeve. Figure 7 is also the amount of wear on the carbon vane. This is a graph showing. 1...Rotary compressor, 2...Casing, 3...
Cylindrical center housing, 6...rotating sleeve,
6a...Inner circumferential surface, 6b...Outer circumferential surface, 7...Air layer, 8...Rotor, 12...Vane, 15...Suction port, 16...Discharge port, 17...Anodic oxide coating,
18...Solid lubricant, 19...Si particles, 20...
recess.

Claims (1)

[Scope of 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; A rotary compressor comprising a vane fitted in a groove formed in a rotor, and the outer end surface of the vane is brought into contact with a rotating sleeve to divide a space between the rotating sleeve and the rotor into a plurality of working chambers. The sleeve is made of Al-Si alloy,
An anodic oxide film is formed on the inner and outer peripheral surfaces of the rotary sleeve, and the Si particles exposed on the anodic oxide film surface on at least the outer peripheral surface of the rotary sleeve are removed by the Si removal treatment, and solid lubrication is applied to the recesses. A rotary sleeve for a rotary compressor, characterized in that an agent is embedded therein.