JPH0448955B2 - - 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 in a cylindrical housing, and a rotor is provided eccentrically with respect to the rotary sleeve. A rotary compressor is well known in which the outer end surfaces of a plurality of vanes supported by a rotor 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 by being pressed against the inner circumferential 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 No. 58-8596, the present applicant has developed a rotary compressor by improving the wear resistance of carbon vanes, which are lightweight and have excellent adhesion to mating materials such as rotary sleeves, to increase drive torque. In order to reduce this, a proposal has already been made in which the vane's mating material is made of an Al--Si alloy, an anodic oxide film (alumite) is formed on the mating material, and the vane is further post-treated. (Objective of the Invention) The present invention further develops the technology of the above-mentioned prior application by applying it to a rotary sleeve of a rotary compressor having a rotary sleeve. By adopting this, it is possible to reduce as much as possible the sliding resistance that may occur between the rotating sleeve made of Al-Si alloy and its housing, thereby preventing seizure or increased load. The aim is to provide a rotary compressor that does not require a rotary compressor. (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 rotary sleeve is made of an Al-Si alloy, and has an anodic oxide coating formed on the inner and outer circumferential surfaces of the rotary sleeve, and a wear-resistant resin layer formed on at least the outer circumferential surface of the rotary sleeve. It is something. (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). It is rotatably supported within the casing 2 without lubrication. (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 in reality it is extremely small, 30 to 50 μm.) 8 is inside the casing 2, A rotor that is rotatably provided with its axis eccentric to the axis of the rotating sleeve 6, and has a shaft 8 that protrudes 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. In the rotor 8, four grooves 11, 11 extending from the outer surface to the vicinity of the shaft center are formed so as to be perpendicular to each other, and in each groove 11, a carbon vane 12 is installed on the inner peripheral surface of the rotating sleeve 6. It is slidably inserted in the radial direction so that it can protrude toward 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. Note that 14 is a ring-shaped side seal that is embedded in the inner wall surface of the side housings 4 and 4 and receives the thrust of the rotating sleeve 6, and 15 and 16 are provided in the side housing 4 on the side opposite to the drive side of the rotor 8. They are an inlet and an outlet. On the other hand, as shown in FIG. 3, the rotating sleeve 6 made of an Al-Si alloy is anodized (anodized) so that its inner circumferential surface 6a and outer circumferential surface 6 are anodized.
Anodic oxide films (alumite) 17, 17 are formed on b. The thickness of the anodic oxide films 17, 17 is preferably about 100 to 300 μm. By alumite treatment of this rotating sleeve 6,
Thermal expansion of the rotating sleeve 6 is suppressed, and thermal deformation, particularly local deformation, of the rotating sleeve 6 is suppressed. Also,
Due to the increased hardness of the Al base, a hardness balance is achieved with the hardness of the Si particles, so that only the Si particles protrude onto the surface of the inner peripheral surface 6a of the rotating sleeve 6 and pull the outer end surface 12a of the vane 12. The phenomenon of scratching and wear can be effectively prevented.
Furthermore, since the outer circumferential surface 6b of the rotating sleeve 6 is appropriately roughened by the alumite treatment, the adhesion with the resin coating described later is improved. Next, a wear-resistant resin layer 18 is formed on the outer peripheral surface 6b of the alumite-treated rotating sleeve 6 by coating. The resin materials used for coating the wear-resistant resin layer 18 include 10 to 120 parts by volume of a solid lubricant and 5 parts of a scaly metal per 100 parts by volume of the wear-resistant resin.
~50 parts by volume, preferably mixed in a dispersed state.
Epoxy resin or the like may be used as the wear-resistant resin, and known solid lubricants such as molybdenum disulfide, boron nitride, carbon-based lubricants such as graphite, and fluororesin powder can be used as the solid lubricant. The scale-like metal pieces are intended to improve the heat resistance and peeling resistance of the coating layer, and for example, aluminum may be used. For example, it is preferable to use a binder based on an epoxy resin with excellent heat resistance and abrasion resistance, mixed with flaky Al and fluororesin powder with excellent lubricity. The flaky Al is preferable in terms of improving the shear of the resin layer 18 itself, the adhesion (bondability) with the base material (rotating sleeve), and the heat resistance of the resin layer. If the content of scaly metal is less than 5 parts by volume, the amount of wear will increase due to the lack of heat resistance and peeling resistance of the coating, and if it is more than 50 parts by volume, the driving torque will increase due to decreased lubricity. The amount of wear also increases.
If the solid lubricant is less than 10 parts by volume, the driving torque and coating wear will increase due to insufficient lubricity, and if it is less than 120 parts by volume, the holding power of the solid lubricant by the resin will be weak and the lubricant will separate from the coating. It falls off and causes a decrease in lubricity. The layer thickness of this wear-resistant resin layer 18 is 100 to 300μ
The degree is appropriate. In this way, by coating the anodic oxide film 17 on the outer peripheral surface 6b of the rotating sleeve 6 with resin, the inner peripheral surface 3a of the cylindrical center housing 3 is coated with resin.
This will reduce the sliding resistance. A durability test was conducted on the rotating sleeve 6 configured as described above. The test conditions are as follows. The cylindrical center housing 3 is made of an Al-based alloy, and the inner peripheral surface 3a is plated with hard Cr (roughness of 2 μm or less after polishing). The rotating sleeve 6 is made of Al-Si alloy,
Hard alumite treatment was applied to the inner circumferential surface 6a and the outer circumferential surface 6b. Table 1 shows the details of the composition of the Al-Si alloy.

[Table] In addition, samples with Si content of 7% and 15% were also prepared for comparison. Details of the composition of the wear-resistant resin layer 18 are shown in Table 2.

[Table] Pump capacity used: 400c.c. Pump rotation speed: 5000rpm Test time: 10Hr Figure 4 shows the results of the amount of variation 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] In Figure 4, × indicates the Si content is 7%■
indicates that the Si content is 15%. In Fig. 4, first, when no alumite treatment is applied, those with resin coating ○ show lower driving torque than those without resin coating ○, but after 10 hours, the initial This increases by 20 to 30% compared to the drive torque, and the fluctuations in the drive torque are large. On the other hand, the alumite-treated one without resin coating is not much different from the one without alumite treatment or resin coating, but the initial driving torque of the one with resin coating is,
It can be seen that not only is the driving torque lower than that of alumite treatment without ○ and resin coating ○, but also that the driving torque hardly changes even after 10 hours. It can also be seen that the higher the Si content, the lower the driving torque. Figure 5 shows the measurement results of the amount of wear on the outer circumferential surface 6b of the rotating sleeve 6 after the durability test (after 10 hours).The one without resin coating caused seizure regardless of whether it was anodized or not. Even with resin coating (○) and those without alumite treatment (○), although seizure did not occur, abnormal wear occurred locally, and it is thought that seizure would occur with longer operation. . Compared to these, those with alumite treatment and resin coating have an overwhelmingly smaller amount of wear. In this case, as is clear from the comparison between the resin coating (○) and the alumite treatment (○) and the alumite treatment (○), the alumite treatment causes thermal deformation of the rotating sleeve 6, especially local thermal deformation. It is recognized that this can be effectively prevented. Furthermore, Fig. 6 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).
It is shown that preventing thermal deformation of the material is most effective, and that if a resin coating is applied on top of that, the amount of wear can be further reduced.
Looking at it a little differently, the sliding resistance between the casing 2 and the rotating sleeve 6 is due to the carbon vane 12.
It has been shown that by reducing the sliding resistance between the rotating sleeve 6 and the casing 2, the amount of wear on the carbon vane 12 can also be effectively reduced. It shows. (Effect of the invention) As is clear from the above explanation, the present invention has the following effects:
An anodized coating is formed on the rotating sleeve, and at least a wear-resistant resin layer is formed on the outer circumferential surface, which reduces sliding resistance on the outer circumferential surface of the rotating sleeve, improves wear resistance, and reduces driving torque. I am now able to do this. In the above embodiment, the resin coating was applied only to the outer circumferential surface of the rotating sleeve to reduce the wear of the carbon vanes, but it is also possible to apply the resin coating to the inner circumferential surface of the rotating sleeve. Needless to say.

[Brief explanation of the drawing]

Figure 1 is a front cross-sectional view of the rotary compressor, Figure 2 is a cross-sectional view of Figure 1, Figure 3 is an enlarged cross-sectional view of section A in Figure 2, and Figure 4 shows the presence or absence of alumite treatment and resin coating. FIG. 5 is a graph showing the amount of variation in drive torque depending on the presence/absence, FIG. 5 is a graph showing the amount of wear on the outer circumferential surface of the rotating sleeve, and FIG. 6 is a graph showing the amount of wear on the carbon vane. 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...Abrasion-resistant resin layer.

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,
Rotation of a rotary compressor, characterized in that an anodized coating is formed on the inner and outer circumferential surfaces of the rotary sleeve, and a wear-resistant resin layer such as epoxy resin is formed on at least the outer circumferential surface of the rotary sleeve. sleeve.