KR102588585B1 - The production method of the air foil bearing - Google Patents

Abstract

The present invention relates to a method of manufacturing an airfoil bearing. The method of manufacturing an airfoil bearing according to this embodiment includes a pretreatment step (ST100) of flattening the raw material to be manufactured into an airfoil bearing, removing foreign substances, and cutting the raw material to a certain length; Coating a film on which a portion to be etched is printed on the surface of the pretreated raw material (ST200); Attaching a light film to the upper surface of the raw material coated with the film and performing exposure by irradiating light (ST300); A step of removing the film on which the portion to be etched is printed by spraying an alkaline solution on the exposed raw material (ST400); A step of spraying an etching solution on the raw material to perform etching (ST500); And a step (ST600) of removing foreign substances remaining in the etched raw material, wherein the pretreatment step (ST100) connects a plurality of components and raw materials constituting the airfoil bearing to the cut raw material. It further includes a step of forming a bridge (ST110).

Description

The production method of the air foil bearing}

The present invention relates to a method of manufacturing an airfoil bearing, and more specifically, to manufacture an airfoil bearing through an etching method to achieve stable production without an expensive progressive mold.

In general, so-called gas bearings, which support the rotating shaft of high-speed rotating equipment such as compressors, turbines, and superchargers, and do not use lubricating oil but use air or gaseous fluid as the working fluid, are largely divided into static pressure bearings and dynamic pressure bearings. It can be classified as:

Hydrostatic bearings are a form of load-bearing capacity that is achieved by forcibly supplying air or gas pressurized by an external compressor between bearings. Instead of requiring a pressure source (external pressurizing device), they can support the shaft even when the shaft is not rotating. Therefore, bearing damage due to solid friction can be avoided.

In contrast, dynamic pressure bearings are a form of load capacity that is obtained by increasing the pressure by drawing surrounding air or gas between the bearings as the shaft rotates. Instead, they do not require a separate pressure source, but are necessary when starting and stopping the rotating body. Solid friction occurs and the bearing life is shortened, so coating of solid lubricant on the bearing surface is necessary to prevent this.

Among dynamic bearings, air foil bearings are implemented by overlapping curved thin plates to create a bearing surface. They are applied in the form of air foil radial bearings that support radial loads and air foil thrust bearings that support axial loads. It is becoming.

Among these, various examples of air foil thrust bearings implemented in the form of thrust bearings to support axial loads are registered in the Korean Registered Patent Publication No. 10-0360240, Registered Patent Publication No. 10-0590139, and Registered Patent Publication No. 10-0360240. It is disclosed in No. 10-0954066, etc.

The air foil thrust bearing consists of a disc-shaped base pad with a through hole for the drive shaft to pass through at the center and fixed to the bearing housing, a bump foil radially attached to the upper surface of the base pad and resilient to axial force, and , It consists of a top foil that covers a plurality of bump foils and is attached to the base pad and faces the thrust pad (also called 'collar') of the drive shaft.

The air foil thrust bearing draws surrounding air between the thrust pad of the drive shaft and the top foil as the drive shaft rotates to form an air layer to support the axial load of the drive shaft.

Airfoil bearings having such characteristics are manufactured using progressive molds for mass production.

The progressive mold has the advantage of being able to mass-produce precision products at a high speed, but the investment cost is very high, and if the pitch hole is not accurately centered during processing, it causes problems such as product defects or reduced precision.

For example, in order to manufacture an air foil bearing, separate molds must be prepared for the top foil of the thrust bearing, the top foil of the bump foil and plate and journal bearing, and the bump foil and middle foil, so the investment cost is very high. The problem that occurred was caused.

Republic of Korea Patent No. 10-0360240

The present invention was made to solve the above problems, and relates to a method of manufacturing an air foil bearing that can manufacture the air foil bearing through etching processing, a chemical corrosion method, without manufacturing the air foil bearing through a plurality of molds. will be.

The present invention for achieving the above object includes a pretreatment step (ST100) of flattening the raw material to be manufactured into an air foil bearing, removing foreign substances, and cutting the raw material to a certain length; Coating a film on which a portion to be etched is printed on the surface of the pretreated raw material (ST200); Attaching a light film to the upper surface of the raw material coated with the film and performing exposure by irradiating light (ST300); A step of removing the film on which the portion to be etched is printed by spraying an alkaline solution on the exposed raw material (ST400); A step of etching by spraying an etchant on the raw material (ST500); And a step (ST600) of removing foreign substances remaining in the etched raw material, wherein the pretreatment step (ST100) connects a plurality of components and raw materials constituting the airfoil bearing to the cut raw material. It further includes a step of forming a bridge (ST110).
The airfoil bearing includes both journal bearings and thrust bearings.
The bridge forming step (ST110) is formed in an area excluding the location where friction or contact occurs due to rotation of the rotor. When the air foil bearing is a journal bearing, a plurality of bridges are formed at both ends in the longitudinal direction. It is characterized by being formed.
The bridge forming step (ST110) is formed in an area excluding the location where friction or contact occurs due to rotation of the rotor, and the air foil bearing is formed as a top foil or bump foil of the thrust bearing. In one case, a plurality of bridges are formed at a location where welding is to be performed with the plate.
The pretreatment step (ST100) is characterized by flattening to maintain constant flatness according to the position of the raw material.

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The manufacturing method of an airfoil bearing according to an embodiment of the present invention enables mass production without using an expensive progressive mold for manufacturing, thereby reducing initial investment costs and minimizing separate maintenance costs.

The method of manufacturing an airfoil bearing according to an embodiment of the present invention improves safety by forming a bridge by avoiding a location where friction occurs with the rotor.

1 is a flowchart showing a method of manufacturing an airfoil bearing according to an embodiment of the present invention.
Figure 2 is a diagram showing a journal bearing installed on the rotor of an electric compressor according to an embodiment of the present invention.
Figure 3 is a diagram showing a state in which a bridge is formed in a journal bearing according to an embodiment of the present invention.
Figure 4 is a diagram showing a state in which a thrust bearing according to an embodiment of the present invention is installed on the rotor of an electric compressor.
Figure 5 is a diagram showing a portion where a thrust bearing rubs against a rotor and a portion where it is welded according to an embodiment of the present invention.
6 to 7 are diagrams showing a state in which a bridge is formed in a thrust bearing according to an embodiment of the present invention.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention. The thickness of lines or sizes of components shown in the attached drawings may be exaggerated for clarity and convenience of explanation.

In addition, the terms described below are terms defined in consideration of functions in the present invention, and may vary depending on the intention of the user or operator or precedent. Therefore, definitions of these terms should be made based on the content throughout this specification.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. The attached FIG. 1 is a flowchart showing a method of manufacturing an airfoil bearing according to an embodiment of the present invention, and FIG. 2 is a diagram showing a journal bearing installed on the rotor of an electric compressor according to an embodiment of the present invention. 3 is a diagram showing a state in which a bridge is formed in a journal bearing according to an embodiment of the present invention, and Figure 4 is a diagram showing a state in which a thrust bearing according to an embodiment of the present invention is installed in the rotor of an electric compressor. It is a drawing.

Referring to the attached FIGS. 1 to 4, the method for manufacturing an air foil bearing according to an embodiment of the present invention is to use an existing progressive mold when manufacturing a journal bearing or thrust bearing surrounding the rotor of an electric compressor installed in a vehicle. We aim to manufacture airfoil bearings that can be mass-produced at low cost and have improved quality and safety through a chemical etching process rather than a molding method.

To this end, the present invention includes a pretreatment step (ST100) of flattening the raw material to be manufactured into an air foil bearing, removing foreign substances, and cutting the raw material to a certain length; Coating a film on which a portion to be etched is printed on the surface of the pretreated raw material (ST200); Attaching a light film to the upper surface of the raw material coated with the film and performing exposure by irradiating light (ST300); A step of removing the film on which the portion to be etched is printed by spraying an alkaline solution on the exposed raw material (ST400); A step of etching by spraying an etchant on the raw material (ST500); And a step (ST600) of removing foreign substances remaining in the etched raw material, wherein the pretreatment step (ST100) connects a plurality of components and raw materials constituting the airfoil bearing to the cut raw material. It further includes a step of forming a bridge (ST110).

The air foil bearing includes both a journal bearing 100 and a thrust bearing 200, and among the air foil bearings, the journal bearing 100 includes a top foil 110 surrounding the rotor 10 on the outside, and the top foil ( It includes a middle seam foil 120 surrounding the middle seam foil 110) from the outside, and a bump strip 130 surrounding the middle seam foil from the outside.

The journal bearing 100 is inserted into the rotor 10 of the electric compressor, and is inserted into the front end and the rear end based on the axial direction. For reference, the bump strip 130 consists of a lower bump strip and an upper bump strip.

Together with the journal bearing 100, the thrust bearing 200 includes a plate 210 inserted into the rear end of the rotor 10, and a plurality of bump foils 220 welded along the circumferential direction of one surface of the plate 210. ), and a plurality of top foils 230 welded in the circumferential direction of the plate 210.

The journal bearing 100 configured in this way is such that when the rotor 10 rotates, the rotor 10 and the journal bearing 100 come into contact with each other in the section shown by the arrow in the outer circumferential direction of the journal bearing 100. This causes friction.

In the present invention, the journal bearing 100 is manufactured using an etching method using a chemical corrosion method, so unlike existing progressive molds, the position of the bridge 300 is very important.

In the preprocessing step (ST100), a bridge 300 is formed on the cut raw material to connect the raw material and a plurality of components constituting the air foil bearing (ST110). The bridge 300 is formed in an area excluding the location where friction or contact occurs as the rotor 10 rotates. In the case of the journal bearing 100, a plurality of bridges 300 are formed at both ends in the longitudinal direction. is formed

The bridge 300 is provided to maintain a fixed state without being separated from the raw material. For example, when manufacturing individual components such as the top foil 110 and the middle seam foil 120, the bridge 300 is located on the upper side in the longitudinal direction than the position where friction or contact occurs due to rotation of the rotor when viewed from the top. and is formed at the lower end.

For example, when the top foil 110 shown in the drawing is molded into a ring shape, the above position corresponds to an end fixed by the key 2, so that it does not come into contact with the outer peripheral surface of the rotating rotor 10. The bridge 300 may be formed in plural numbers, and the number is not particularly limited.

In this way, when etching molding is performed on the top foil 110 or middle seam foil 120 constituting the journal bearing 100 by etching the raw material 20, the bridge 300 causes the final assembled It can be used stably without problems caused by friction between the journal bearing 100 and the rotor 10.

In particular, when the journal bearing 100 is molded as above, the air film formed in the gap (not shown) between the rotor 10 and the journal bearing 100 is maintained constant, and the rotational stability of the rotor 10 is improved, Damage to the rotor 10 or generation of heat due to friction can be minimized, thereby improving the operational safety of the electric compressor.

Referring to the attached FIGS. 4 to 7, in the pre-processing step (ST100), the air foil bearing along with the above-described journal bearing 100 is used as the top foil 230 or bump foil of the thrust bearing 200. In the case of the foil 220, a plurality of bridges 300 are formed at the location where welding is to be performed with the plate 210.

The journal bearing 200 is inserted in the axial direction of the rotor 10, but is not in the form of surrounding the outside of the rotor 10, but is provided for damping in the radial direction in the axial direction of the rotor 10, and is provided for damping in the radial direction of the rotor 10. ) Minimize the external force applied in the axial direction.

Since the bump foil 220 is spot welded along the circumferential direction on one surface of the plate 210, the welded portion does not come into direct contact with the rotor 10.

Since the portion shown with a dotted line of the top foil 230 corresponds to a portion where a load is applied and contact occurs when the rotor 10 moves in the axial direction, the bridge 300 is not formed in the area shown with the dotted line. This may be desirable (see Figure 7).

Referring to the attached FIG. 6, the bridge 300 and the bump foil 220 are not installed because friction is generated in the area shown by the dotted line in the drawing due to direct contact with the rotor 10. It is preferable that the bridge 300 is formed at the end where the split 221 is partially formed so that problems due to friction do not occur.

Referring to the attached FIG. 7, the top foil 230, like the bump foil 220 described above, is spot welded along the circumferential direction of the plate 210, and the welded portion is in direct contact with the rotor 10. It doesn't work.

Therefore, in the case of the top foil 230, the bridge 300 is formed at the position shown in the drawing, and the area shown by the dotted line generates friction due to direct contact with the rotor 10, so the bridge 300 is not installed. It is desirable.

In the pretreatment step (ST100), the raw material is flattened, foreign substances are removed, and the raw material is cut to a certain length. For example, when the raw material is flattened to maintain constant flatness depending on the location, the flattening may be performed, for example, by rolling the raw material, or the raw material may be flattened in other ways. there is.

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In this way, after the raw material to be manufactured into the air foil bearing is stably flattened, foreign substances or oil stains remaining on the surface of the raw material are removed. Since the above foreign substances remain on the surface during production or movement of raw materials, it is desirable to remove them before etching.

A film on which the part to be etched is printed is coated on the surface of the raw material pretreated in this way (ST200), and the film is patterned in a shape corresponding to each component that constitutes a journal bearing or thrust bearing made of an air foil bearing. is formed The film is produced without error by drawing the exact shape of the journal bearing or thrust bearing in advance using CAD or a similar program.

The exposure process attaches a light film to the upper surface of the film-coated raw material. After exposure, it is cured by applying ultraviolet rays or heat to form a cured part and a non-cured part depending on the presence or absence of a pattern (ST300).

Then, the exposed raw material is sprayed with an alkaline solution to remove the film on which the part to be etched is printed (ST400). Then, etching is performed by spraying an etching solution on the raw material (ST500).

Since foreign substances may remain in the etched raw material, foreign substances are removed from the raw material once more (ST600) to maintain a clean surface.

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Finally, through inspection of the final finished product in the etched state, defective products with any abnormalities can be classified separately.

As described above, the present invention has been described with reference to the embodiments shown in the drawings, but these are merely exemplary, and various modifications and other equivalent embodiments can be made by those skilled in the art. You will understand that it is possible. Therefore, the true technical protection scope of the present invention should be determined by the scope of the patent claims below.

10: rotor
100: journal bearing
110: top foil
120: Middle seam foil
130: bump strip
200: Thrust bearing
210: Plaid
220: bump foil
230: top foil

Claims (8)

A pretreatment step (ST100) of flattening the raw material to be manufactured into an air foil bearing, removing foreign substances, and cutting the raw material to a certain length;
Coating a film on which a portion to be etched is printed on the surface of the pretreated raw material (ST200);
Attaching a light film to the upper surface of the raw material coated with the film and performing exposure by irradiating light (ST300);
A step of removing the film on which the portion to be etched is printed by spraying an alkaline solution on the exposed raw material (ST400);
A step of etching by spraying an etchant on the raw material (ST500); and
Comprising a step (ST600) of removing foreign substances remaining in the etched raw material,
The pretreatment step (ST100) further includes forming a bridge (ST110) connecting the raw material and a plurality of components constituting the airfoil bearing to the cut raw material. According to claim 1,
A method of manufacturing an airfoil bearing, wherein the airfoil bearing includes both a journal bearing and a thrust bearing. delete According to claim 1,
The bridge forming step (ST110) is formed in an area excluding the location where friction or contact occurs due to rotation of the rotor. When the air foil bearing is a journal bearing, a plurality of bridges are formed at both ends in the longitudinal direction. A method of manufacturing an air foil bearing, characterized in that it is formed. According to claim 1,
The bridge forming step (ST110) is formed in an area excluding the location where friction or contact occurs due to rotation of the rotor, and the air foil bearing is formed as a top foil or bump foil of the thrust bearing. In one case, a method of manufacturing an air foil bearing, characterized in that a plurality of bridges are formed at a position where welding with the plate is to be performed. delete According to claim 1,
The pretreatment step (ST100) is a method of manufacturing an air foil bearing, characterized in that flatness is performed to maintain constant flatness according to the position of the raw material. delete

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