JPH0459477B2 - - 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. Rotary compressors in which the rotating sleeve is supported by a fluid support device are suitable for superchargers in internal combustion engines, in particular in motor vehicle engines.

<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 tips. 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, due to the high internal pressure on the discharge side, if the rotary sleeve moves toward the discharge side and comes into direct contact with the center housing, scuffing may occur at the contact location, which may result in poor rotation of the rotary sleeve.

When the rotating sleeve approaches the discharge side and contacts the center housing, the rotating sleeve does not make contact at one location on the inner peripheral surface of the center housing;
Since it became clear that contact occurs in a wide area, the inventor of the present application created an inlet at the beginning of the contact area in order to increase the air flow in the contact area and increase the bearing load force in the air bearing chamber. A proposal to establish a chamber and communicate its inlet with the atmosphere or the discharge chamber (patent application 1983-
28608), but subsequent research led to the discovery of a means to further improve the bearing load force in the air bearing chamber.

<Problem of the Invention> An object of the present invention is to improve the fluid support device of the rotating sleeve that allows air to flow into the contact area on the inner circumferential surface of the center housing on the discharge side to more reliably prevent direct contact between the rotating sleeve and the center housing. It's about doing.

<Technical Means for Achieving the Object> As a technical means for achieving the object, the device of the present invention provides a contact area on the inner circumferential surface of the center housing discharge side, which the rotating sleeve attempts to contact due to internal high pressure. The discharge chamber is provided with a plurality of inlets communicating with the discharge chamber or a working chamber partitioned by two adjacent vanes immediately before ventilation via check valves.

Air flowing in from the inlet located on the upstream side flows through the contact area as the rotating sleeve rotates and increases the bearing load force in the upstream area, but is insufficient to increase the bearing load force in the downstream area. However, the air flowing in from the inlet located on the downstream side flows downstream of the contact area and increases the bearing load force on the downstream side. At this time, since the inlet is provided with a check valve, the air inside the air bearing chamber, which is increased by the rotation of the rotary sleeve, does not flow back. As described above, since there is an inlet having a plurality of check valves, an appropriate amount of air flows over the entire contact area, increasing the bearing load force in the entire contact area.

<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 a 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 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.
Two adjacent vanes 16 form a working chamber 43,
The pressure in the working chamber increases as it moves from the suction side to the discharge side.
It reaches its maximum level just before it communicates with the discharge chamber 41 via 2. An air bleed port 44 is provided in this maximum pressure working chamber 43. Inflow ports 71 are provided at three locations: the starting end of the contact area where the rotary sleeve 30 comes into contact on the discharge side inner peripheral surface of the center housing 22, a point P where the air bearing chamber 40 receives the maximum pressure, and an intermediate point therebetween. Inflow passages 45 extending from the air bleed port 44 to each inflow port 71 are provided in parallel, and a check valve 76 is interposed in each inflow passage 45 . The inlet passage 45 passes through the inside of the housing, but is shown as passing through the outside by imaginary lines for ease of viewing.

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 inlet passage 45 communicates with an inlet 71 carved in the inner peripheral surface of the center housing 22 . High pressure air is supplied from the inlet 71 to the air bearing chamber 40 between the center housing 22 and the rotating sleeve 30.
flows into.

As shown in FIG. 3, the extraction port 44 is connected to the discharge chamber 41.
from the air bleed port to the center housing 22.
Inlet ports 7 are provided at three locations between the starting end of the contact area, the position P where the air bearing chamber 40 receives the maximum pressure, and the position P where the air bearing chamber 40 receives the maximum pressure.
1 may be provided in parallel, and a check valve 76 may be interposed in the parallel inflow paths.

As shown in FIG. 4, the fourth inlet 71 is provided at a position further downstream from the position P where the air bearing chamber 40 receives the maximum pressure, and the fourth inlet 71 is placed in the same manner as the other three inlets 71. When the air bleed port 44 is communicated through the check valve 76 and the inflow passage 45, the high-pressure air circulates sufficiently not only to the contact area of the center housing 22 but also to the suction side. The load force is also increased, and contact of the rotating sleeve 30 with the inner circumferential surface on the suction side of the center housing is also prevented.

As shown in FIGS. 5 to 8, the inflow channel 45
The inlet 71 as an outlet is formed in a symmetrical groove, but the groove may have any shape as long as it expands in the axial direction. For example, it may be a rectangular groove divided into left and right sides as shown in Fig. 5, a single rectangular groove extending left and right as shown in Fig. 6, a herringbone groove as shown in Fig. 7, or a collection of elongated striped grooves as shown in Fig. 8. .

When the illustrated rotary compressor rotates, high-pressure air flows in all at once from three or four inlet ports 71 provided from the start end to the end of the contact area.
Moreover, since the air inside the air bearing chamber increased by the rotation of the rotating sleeve does not flow backwards due to the provision of a check valve, an appropriate amount of air flows over the entire contact area and the air inside the air bearing chamber 40 is increased. The bearing load force across the entire contact area is increased and direct contact between the rotating sleeve 30 and the center housing 22 is prevented.

<Effects of the Invention> As mentioned above, since the device of the present invention is equipped with a plurality of distributed inlets with check valves in the contact area, the air bearing chamber is reduced compared to a device with a single inlet. The bearing load force across the entire contact area increases, and the effect of preventing direct contact between the rotating sleeve and the center housing is significantly improved.

[Brief explanation of drawings]

Fig. 1 is a view showing an end face of a rotary compressor equipped with a device according to an embodiment of the present invention with the rear side housing removed, and Fig. 2 is a slightly reduced view of a cross section taken along the - line in Fig. 1. be. FIGS. 3 and 4 are views corresponding to FIG. 1 of different embodiments, and FIGS. 5 to 8 are developed views of the inlet of each embodiment. 10... Rotor, 16... Vane, 22... Center housing, 30... Rotating sleeve, 40
... air bearing chamber, 41 ... discharge chamber, 43 ... working chamber, 71 ... inlet, 76 ... check valve.

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 removable, the center housing and a thin-layer air bearing chamber formed between the rotary sleeve and a contact on the inner circumferential surface of the center housing discharge side with which the rotary sleeve tends to come into contact due to internal high pressure. A plurality of inflow ports are provided in the area, and each inflow port communicates via a check valve with a discharge chamber or an operating chamber partitioned by two adjacent vanes immediately before ventilating the discharge chamber. A fluid support device for a rotating sleeve of a rotary compressor.