JPH0138314Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a vane-type rotary compressor that can be used as a supercharger for an internal combustion engine, and more specifically, the present invention relates to a vane-type rotary compressor that can be used as a supercharger for an internal combustion engine. It is related to the machine.

The applicant of the present invention previously developed a vane-type rotary compressor (Japanese Patent Application No. 162025/1983) in which a rotary sleeve interposed between a rotor and a center housing is rotatably supported by a compressible fluid such as air. I made a suggestion, but
The compressor has a rotating sleeve that rotates with the vane, preventing heat generation and wear caused by sliding of the vane tips, making it ideal for use as a supercharger for automobile engines that operate over a wide range of rotational speeds. It can be said that there is. However, when used for a long time under high temperatures,
Occasionally, there was a problem that the outer peripheral surface of the rotating sleeve came into contact with the inner peripheral surface of the center housing, causing scuffing or seizure. After investigating the cause, we found that if there is a difference in the coefficient of thermal expansion between the center housing and the rotating sleeve, the width of the air bearing chamber, which is the gap between the inner and outer circumferential surfaces of both, changes at high temperatures, reducing the bearing capacity. It has become clear that the outer circumferential surface comes into contact with the inner circumferential surface of the center housing more easily.

An object of the present invention is to provide a rotary compressor in which the bearing capacity of the air bearing chamber does not deteriorate even when used at high temperatures.

In order to achieve the above object, the gist of the present invention is to form the center housing and the rotating sleeve from materials having the same coefficient of thermal expansion, thereby creating an air bearing chamber that is formed as a gap between the inner and outer peripheral surfaces of the two. The rotary compressor is capable of keeping the width constant regardless of temperature.

The compressor of the present invention will be explained based on an embodiment shown in the drawings. As shown in FIGS. 1 to 3, a rotary shaft 12 integral with the rotor 10 of the compressor is supported by bearings 18 and 19 in front and rear side housings 21 and 23, and the shaft end on the front side includes: Pulley 1 receives the rotational drive of the engine
4 is installed. A vane 16 is fitted into each of the plurality of vane grooves 15 of the rotor 10 so as to be removable and removable, and the tip of the vane 16 contacts a rotating sleeve 30 surrounding the rotor 10 . The rotating sleeve 30 is housed within the center housing 22, and an air bearing chamber 40 having a thickness of 0.02 mm to 0.15 mm is interposed between the two. A rear cover 24 is fixed to the back surface of the rear side housing 23 via a gasket, and a discharge chamber 41 and a suction chamber 51 are provided in the rear cover. The discharge chamber 41 communicates with a discharge hole 42 of the rear side housing 23 via a discharge valve 60, and the discharge hole communicates with a compression chamber 43 between the rotor 10 and the rotating sleeve 30. The suction chamber 51 communicates with an intake chamber 53 on the opposite side via a suction hole 52 . An annular groove 26 is provided on the sliding surfaces of the front and rear side housings 21 and 23 with respect to the rotating sleeve 30, and the non-lubricated sliding member 25 is fitted into the annular groove 26. Fixing bolt 27
penetrates the thick part 28 of the center housing 22 and fastens the front and rear housings 21, 23, the center housing 22, and the rear cover 24 in the axial direction.

As shown in FIGS. 2 and 3, the discharge chamber 41
A high pressure hole 44 passing through the rear side housing 23 and a high pressure groove 45 provided on the discharge side end surface of the inner surface of the center housing 22 that intersects with the high pressure hole
and the center housing 22 from the high pressure groove 45.
is connected to the discharge side of the air bearing chamber 40 through a high pressure path consisting of a plurality of high pressure introduction holes 46 extending in the axial direction of communicate. or,
The discharge chamber 41 includes a high-pressure inner hole 48 that penetrates diagonally inward through the rear side housing 23 from a discharge hole 42, and a rear side housing 23 that intersects with the high-pressure inner hole.
It communicates with the bottom of the vane groove 15 of the vane 16 on the discharge side via the high pressure vane groove 49 on the inner surface. The suction chamber 51 includes an air return hole 56 that passes through the suction side of the center housing 22, a low pressure groove 55 that intersects with the air return hole and runs around the suction side of both end faces of the center housing 22, and the low pressure groove and the air bearing chamber. It communicates with the suction side of the air bearing chamber 40 through a low pressure path consisting of an air return passage 57 that connects the air bearing chamber 50 and a low pressure hole 54 that extends from the suction chamber 51 through the rear side housing 23 and reaches the low pressure groove 55. An exhaust hole 50 is branched from the air return hole 56, and the exhaust hole is provided with a check valve if necessary. The suction chamber 51 has a low-pressure inner hole 58 that penetrates the rear side housing 23 obliquely inward, and a vane of the vane 16 that comes to the suction side via a low-pressure inner hole 58 that communicates with the low-pressure inner hole on the inner surface of the rear side housing 23. It also communicates with the bottom of the groove 15.

Both the center housing 22 and the rotating sleeve 30 are made of the same high silicon aluminum alloy;
One of the inner and outer circumferential surfaces of both is anodized.

When the rotation of the engine is transmitted to the pulley 14 to drive the compressor, the compression chamber 4 pushed into the vane 16
The temperature of the gas 3 increases due to adiabatic compression. In particular, when the compressor is used as an EGR supercharger, the temperature of the compressor becomes extremely high because it takes in and compresses high-temperature engine exhaust gas, but the center housing 22 and rotating sleeve 30 are made of the same high silicone Since both are made of aluminum alloy, the amount of deformation due to thermal expansion is the same for both. the result,
The width of the air bearing chamber 40 between the inner and outer circumferential surfaces of the two does not substantially change regardless of the temperature, and its bearing capacity is always constant. Therefore, if the width of the air bearing chamber 40, which is the gap between the inner circumferential surface of the center housing and the outer circumferential surface of the rotary sleeve at room temperature, is set so as to optimize the bearing capacity, the air bearing chamber will remain stable even at high temperatures. Since the same width is maintained and sufficient bearing capacity is maintained, contact between the outer circumferential surface of the rotating sleeve and the inner circumferential surface of the center housing will not occur unless there is a major reason. Furthermore, even if they do come into contact, one of the surfaces is covered with an anodic oxide film, so the coefficient of friction between the two is extremely small. Therefore, contact sliding does not lead to scuffing or seizure. It is preferable that the fixing bolt 27 is also made of aluminum and has the same coefficient of thermal expansion as the center housing 22.

The example center housing and rotating sleeve are made of high silicon aluminum alloy, although other aluminum alloys may be used. Aluminum alloy is preferred for weight reduction, but the center housing and rotating sleeve can also be made from ferrous materials such as cast iron and steel.Cast iron has a unique graphite self-lubricating effect. Since the sliding properties are good even when the two come into contact, scuffing and seizure can be sufficiently prevented.

[Brief explanation of the drawing]

1 and 2 are a partially cutaway perspective view and a side sectional view of a rotary compressor according to an embodiment of the present invention,
FIG. 3 is a sectional view taken along the - line in FIG. 2. 10: Rotor, 16: Vane, 22: Center housing, 30: Rotating sleeve.

Claims (1)

[Claims for Utility Model Registration] 1. A rotating sleeve rotatably supported by a center housing, a rotor rotating at an eccentric position of the rotating sleeve, and a vane fitted into the rotor so as to be removable and removable, the center housing In a rotary compressor in which the rotary sleeve is rotatably supported by an air bearing chamber formed between an inner peripheral surface of the center housing and an outer peripheral surface of the rotary sleeve, the center housing and the rotary sleeve have the same coefficient of thermal expansion. A rotary compressor characterized in that the width of the air bearing chamber is maintained constant regardless of temperature. 2. The rotary compressor according to claim 1, characterized in that the center housing and the rotary sleeve are made of aluminum alloy. 3. The rotary compressor according to claim 2, which is a registered utility model, characterized in that an anodized coating is provided on either the inner circumferential surface of the center housing or the outer circumferential surface of the rotary sleeve. 4. The rotary compressor according to claim 1, wherein the center housing and the rotary sleeve are made of iron-based material. 5. The rotary compressor according to claim 1, wherein the fixing bolts passing through the thick part of the center housing are made of a material having the same coefficient of thermal expansion as the center housing.