JPH0152593B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to an improvement in a fluid support device for a rotary sleeve that is rotatably fitted into a center housing of a rotary compressor and rotates together with vanes. In other words, it relates to a device for fluidly supporting a rotary sleeve in a thin air bearing chamber formed between a center housing and a rotary sleeve. A rotary compressor with this fluid support device is suitable for a supercharger of an internal combustion engine, especially an automobile engine.

<Prior art> A vane-type rotary compressor, in which a rotating sleeve is supported by compressible fluid such as air, can be used from low to high speeds because the rotating sleeve rotates with the vane and prevents heat generation and wear caused by sliding of the vane tip. It can be said that this is the most suitable supercharger for automobile engines, etc., which are operated at a wide range of rotation speeds up to. However, during startup, the pressure in the air bearing chamber formed between the inner peripheral surface of the center housing and the outer peripheral surface of the rotating sleeve is low and the rotating sleeve cannot be supported sufficiently.
There was a risk that the rotating sleeve would move to one side and come into direct contact with the center housing, causing scuffing at the contact point, resulting in poor rotation of the rotating sleeve. Also, during operation, if the rotating sleeve moves toward the discharge side and comes into direct contact with the center housing due to the high internal pressure on the discharge side, scuffing will occur at the contact point, causing poor rotation of the rotating sleeve and reducing compressor torque. There is a risk of change.

<Problem of the Invention> An object of the present invention is to provide a fluid support device for a rotary sleeve that prevents direct contact between the rotary sleeve and the center housing during startup and operation to reduce torque fluctuations in a rotary compressor. be.

<Technical Means for Achieving the Object> As a technical means for achieving the object, the device of the present invention uses molded carbon, a carbon fired body, and resin impregnation in the air bearing chamber formed between the center housing and the rotating sleeve. Fine carbon powder, fine powder of tetrafluoride ethylene hexafluoride propylene copolymer resin, zirconium oxide on polyimide resin,
Self-lubricating particles selected from the group consisting of fine powder mixed with at least one of silicon carbide, silicon nitride, alumina, carbon, and tetrafluoroethylene resin are dispersed therein.

The self-lubricating particles in the air bearing chamber adhere to the inner circumferential surface of the center housing and the outer circumferential surface of the rotating sleeve to form a lubricating film, and when the rotating sleeve approaches the center housing, it interposes between them and rolls, preventing direct contact between the two. This prevents scuffing due to direct contact.

The amount of self-lubricating particles is 10% of the total volume of the air bearing chamber.
If it exceeds 10%, the rotational resistance will increase, so it is desirable to keep it below 10%. The lower limit depends on the diameter of the self-lubricating particles and the thickness of the air bearing chamber. For example, if the self-lubricating particles are 1 micron diameter carbon and the air bearing chamber is 100 microns thick, the lower limit is 1 micron.
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<Example> The apparatus of the present invention will be described based on an example shown in the drawings. As shown in FIG. 1, a rotor 10 of the rotary compressor is integrally fixed to a rotating shaft 12, and rotates in the direction of the arrow at an eccentric position of a rotating sleeve 30. A vane 16 is fitted into the vane groove 15 of the rotor 10 so as to be freely removable and removable, and the tip of the vane 16 is in contact with the inner circumferential surface of the rotating sleeve 30. The rotating sleeve 30 is rotatably fitted into the center housing 22,
An air bearing chamber 40 is formed between the two. Although the figure shows the thickness of the air bearing chamber 40 in an exaggerated manner,
The actual thickness is very thin, less than 0.1 mm.
Self-lubricating particles are dispersed in this air bearing chamber 40 . The two adjacent vanes 16 form working chambers 53, 43 on the suction side and the discharge side, and the pressure in the working chambers increases as it moves from the suction side to the discharge side. It reaches its maximum just before it communicates with the discharge chamber via.

As shown in FIG. 2, the rotation shaft 12 of the rotor 10
are front and rear side housings 21, 23
A pulley 14, which receives the rotational drive of the engine, is attached to the front end of the shaft. Rear side housing 23
A rear cover 24 is fixed to the back surface of the pump via a gasket, and a discharge chamber 41 and a suction chamber 5 are connected to the rear cover.
1 is provided. The discharge chamber 41 communicates with a discharge side working chamber 43 partitioned by two adjacent vanes 16 inserted into the discharge side vane groove 15 through the discharge hole 42, and the suction chamber 51 communicates with the suction side through the suction hole 52. It communicates with the working chamber 53. center housing 22,
front and rear side housings 21, 23,
The rear cover 24 is integrally fastened via bolts 27. Self-lubricating particles are dispersed in the air bearing chamber 40 between the rotating sleeve 30 and the center housing 22.

As shown in an exaggerated manner in FIG.
air bearing chamber 4 between 0 and center housing 22
Self-lubricating particles P with a volume ratio of 10% or less are dispersed in 0. Self-lubricating particles P include molded carbon, fired carbon, fine powder of resin-impregnated carbon, fine powder of tetrafluoroethylene-hexafluoropropylene copolymer resin, polyimide resin, zirconium oxide, silicon carbide, silicon nitride, and alumina. ,carbon,
A fine powder mixed with at least one type of tetrafluoroethylene resin is used. Instead of enclosing these fine powders in the air bearing chamber 40, vanes may be formed from molded carbon, fired carbon, resin-impregnated carbon, etc., and the abrasion powder is dispersed in the air bearing chamber 40, forming self-lubricating particles P. You may also make it so that Further, the side housing facing the rotating sleeve is made of tetrafluoroethylene-hexafluoropropylene copolymer resin, polyimide resin, and at least one of zirconium oxide, silicon carbide, silicon nitride, alumina, carbon, and tetrafluoroethylene resin. A solid lubricant made of a mixed material is embedded, and its abrasion powder is dispersed in the air bearing chamber 40 to form self-lubricating particles P.
You may also make it so that

When the illustrated compressor is started, the pressure in the air bearing chamber 40 formed between the inner peripheral surface of the center housing 22 and the outer peripheral surface of the rotating sleeve 30 is low, and the rotating sleeve 30 cannot be supported sufficiently. The rotating sleeve 30 moves to one side and tries to come into contact with the center housing 22, but since the self-lubricating particles P are present between the two, direct contact between the two is prevented. Furthermore, during operation, the rotating sleeve 30 approaches the discharge side and tries to contact the center housing 22 due to the high internal pressure on the discharge side, but the self-lubricating particles P interposed between the two prevent direct contact between the two. to prevent Therefore, the rotating sleeve 30 rotates smoothly without contacting the center housing 22.

<Effects of the Invention> As mentioned above, the device of the present invention prevents direct contact between the rotating sleeve and the center housing with the self-lubricating particles dispersed within the air bearing chamber, so it is different from conventional devices in which self-lubricating particles do not exist within the air bearing chamber. Compared to the above system, this system has the excellent effect of preventing compressor torque fluctuations and scuffing caused by direct contact between the rotating sleeve and the center housing.

[Brief explanation of drawings]

1 and 2 are a cross-sectional view and a longitudinal sectional view of a rotary compressor equipped with an apparatus according to an embodiment of the present invention, and FIG.
The figure is a partially enlarged sectional view of the air bearing chamber of FIG. 1. 10: Rotor, 16: Vane, 22: Center housing, 30: Rotating sleeve, 40: Air bearing chamber, P: Self-lubricating material particles.

Claims (1)

[Claims] 1. A rotary compressor comprising a rotary sleeve rotatably fitted to a center housing, a rotor rotating at an eccentric position of the rotary sleeve, and a vane fitted to the rotor so as to be removable and retractable, the center housing and an air bearing chamber formed between the rotary sleeve, wherein self-lubricating particles having a volume ratio of 10% or less are dispersed in the air bearing chamber, and the self-lubricating particles are molded carbon, Carbon fired body, fine powder of resin-impregnated carbon, fine powder of tetrafluoride ethylene hexafluoride propylene copolymer resin, polyimide resin containing zirconium oxide, silicon carbide, silicon nitride, alumina, carbon, tetrafluoride ethylene resin A fluid support device for a rotary sleeve of a rotary compressor, characterized in that the fluid support device is selected from the group consisting of fine powder mixed with at least one kind.