KR20200114637A - Air foil bearing - Google Patents

Abstract

The present invention provides an airfoil bearing comprising: first and second airfoil plates disposed on both sides of a rotor and supporting rotation of the rotor in both directions; and a preloading means for preloading the first and second airfoil plates in the direction away from the rotor in the axial direction by an elastic restoring force. An object of the present invention is to provide the airfoil bearing with improved operational stability and durability.

Description

Air foil bearing

The embodiment relates to an airfoil bearing.

A bearing is a mechanical element that fixes a rotating shaft at a certain position and supports the shaft's own weight and load applied to the shaft so as to rotatably support it. For example, a ball bearing or journal bearing is a method of supporting a shaft using an oil film, and a foil bearing is a bearing of a method of supporting the shaft by forming a high-pressure air layer between the top foil and the shaft.

When the rotor rotates at high speed, the airfoil bearing supports the axial load by forming pressure by introducing air, which is a viscous fluid, between the rotor or the bearing disk and the contacting foil.

Since the airfoil bearing is effective in supporting a rotating shaft rotating at a high speed, it can be applied to a rotating shaft rotating at a high speed in rotating equipment such as a turbo compressor, a turbo cooler, a turbo generator, and an air compressor.

The airfoil bearing includes a plate, a bump foil disposed on the plate and elastically deformable, and a top foil on the bump foil in contact with the rotating portion. At this time, the bump foil and the top foil are joined on the plate by welding, which requires additional press processing and welding processing processes, and an effort such as welding quality control is required, which increases the product cost of the bearing. Accordingly, an airfoil bearing having a structure that can be assembled without a welding process has been proposed.

In this regard, Korean Patent Registration No. 10-1558489 (registered on October 1, 2015) discloses an assembly-type airfoil bearing, and according to the disclosed contents, the airfoil bearing includes a lower plate having a coupling part and a lower plate of the lower plate. A bump foil plate provided with a bump foil disposed on an upper surface to be elastically deformable and coupled to the coupling portion, and an air foil plate coupled to the coupling portion by having a top foil disposed on the upper surface of the bump foil plate and in contact with the rotating portion. Include.

When the conventional airfoil bearing as described above is driven for a long period of time, as repeated vibrations are applied in the axial direction, a load is concentrated or abrasion occurs due to heat generation. In particular, when the rotating shaft passes a bending critical speed, a large vibration occurs, and problems such as abrasion of the bearing coating and rubbing of the rotating shaft and stator may occur. In addition, when the airfoil bearings are double mounted on the front and rear of the rotor disk, the front and rear bearings shake during high-speed rotation, which may cause the rotor to slide.

Korean Patent Registration No. 10-1558489 (registered on October 1, 2015)

An object of the present invention is to provide an airfoil bearing having improved operational stability and durability by forming a preload between a plurality of bump foil plates or top foil plates. In particular, the present invention is characterized by improving stability and durability by forming a preload based on a rotor disk in an air foil bearing manufactured by simply laminating without welding a foil plate (top foil, bump foil, etc.).

The problem to be solved by the present invention is not limited to the problems mentioned above, and other problems that are not mentioned herein will be clearly understood by those skilled in the art from the following description.

An embodiment includes: first and second airfoil plates disposed on both sides of a rotor and supporting rotation of the rotor in both directions; And a preloading means for preloading the first and second airfoil plates in a direction away from the rotor in an axial direction by an elastic restoring force.

Preferably, the rotor may include a rotor shaft connected to a rotation shaft of a motor, and a rotor disk extending in a radial direction of the rotor shaft and disposed between the first and second airfoil plates.

Preferably, the preloading means may include a mesh damper disposed outside the rotor disk R2 to have a plurality of through holes.

Preferably, the height of the mesh damper in the axial direction may be greater than a separation distance between the first and second airfoil plates.

Preferably, a separation distance ratio between the rotor disk and the first or second airfoil plate to the axial thickness of the first or second airfoil plate may be 0.1 to 0.3.

Preferably, it may further comprise a coupling means for coupling the first and second airfoil plates and the mesh damper.

Preferably, the coupling means may include a plurality of coupling pins penetrating the first and second airfoil plates and the mesh damper.

Preferably, the plurality of coupling pins may be spaced apart at 120° intervals based on the center of the rotor.

According to the embodiment, it is possible to manufacture by laminating an airfoil plate (top foil, bump foil, etc.) on a rotor in a non-welded state, and by forming a preload by elastic restoring force based on the rotor inside the airfoil bearing, the airfoil It can improve the operating stability and durability of the bearing.

According to the embodiment, when the rotor rotates, air adjacent to the airfoil bearing passes through the through hole of the mesh to form a turbulent flow, thereby increasing the heat exchange efficiency of the flowing air and improving the cooling performance of the airfoil bearing.

1 is a cross-sectional view showing an air compressor for a vehicle equipped with an airfoil bearing according to an embodiment of the present invention.
2 is a perspective view of an airfoil bearing according to an embodiment of the present invention.
3 is an exploded perspective view of an airfoil bearing according to an embodiment of the present invention.
4 is a side cross-sectional view of an airfoil bearing according to an embodiment of the present invention.
5 is a perspective view of the mesh damper shown in FIGS. 2 to 4.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, the technical idea of the present invention is not limited to some embodiments to be described, but may be implemented in various different forms, and within the scope of the technical idea of the present invention, one or more of the constituent elements may be selectively selected between the embodiments. It can be combined with and substituted for use.

In addition, terms (including technical and scientific terms) used in the embodiments of the present invention are generally understood by those of ordinary skill in the art, unless explicitly defined and described. It can be interpreted as a meaning, and terms generally used, such as terms defined in a dictionary, may be interpreted in consideration of the meaning in the context of the related technology.

In addition, terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention.

In the present specification, the singular form may include the plural form unless specifically stated in the phrase, and when described as "at least one (or more than one) of A and (and) B and C", it is combined with A, B, and C. It may contain one or more of all possible combinations.

In addition, terms such as first, second, A, B, (a), and (b) may be used in describing the constituent elements of the embodiment of the present invention.

These terms are only for distinguishing the component from other components, and are not limited to the nature, order, or order of the component by the term.

And, when a component is described as being'connected','coupled' or'connected' to another component, the component is not only directly connected, coupled or connected to the other component, but also the component and It may also include the case of being'connected','coupled' or'connected' due to another component between the other components.

In addition, when it is described as being formed or disposed in the "top (top) or bottom (bottom)" of each component, the top (top) or bottom (bottom) is one as well as when the two components are in direct contact with each other. It also includes a case in which the above other component is formed or disposed between the two components. In addition, when expressed as "upper (upper) or lower (lower)", the meaning of not only an upward direction but also a downward direction based on one component may be included.

1 is a cross-sectional view showing an air compressor for a vehicle equipped with an airfoil bearing according to an embodiment of the present invention. Below. The inside represents the direction toward the axis center based on the radial direction of the motor, and the outside represents the opposite direction of the inside.

Referring to FIG. 1, an air foil bearing 1 according to an embodiment of the present invention is installed in a mechanical device having a rotating shaft rotating at high speed. In this embodiment, an airfoil bearing 1 is installed to support the rotating shaft 65 of the blotter motor mounted on the air compressor. (However, this description is only one embodiment, and a mechanical device having a rotating shaft. It can be applied anywhere).

An air compressor for a vehicle includes a housing (H) forming an exterior, an impeller 40 coupled to the front of the housing (H) to compress air, an impeller receiving portion 20 accommodating the impeller 40, and an impeller housing ( 30), a rear cover 50 coupled to the rear of the housing H, and a blotter motor 60 installed in the housing H to rotate and drive the impeller 40.

An air inlet 31 through which external air is introduced is formed in the front center of the impeller housing 30, and air discharge ports 33 are formed on both sides of the front side. The impeller 40 is installed inside the impeller housing 30, and the rotation shaft 65 of the blotter motor 60, which will be described later, is coupled to the hollow penetrating the impeller 40. That is, the impeller 40 is supported by the rotation shaft 65. The air sucked through the air inlet 31 by the impeller 40 is compressed by the impeller 40 and discharged to the air outlet 33.

The blotter motor 60 is inserted into the motor housing 60a inserted inside the housing H. The blotter motor 60 is installed adjacent to the inner circumferential surface of the motor housing 60a and has a stator 63 having a hollow (not shown), a rotating shaft 65 installed through the hollow of the stator 63, and a rotating shaft ( It consists of a rotor that is coupled to the outer peripheral surface of 65).

The rotary shaft 65 can be rotated inside the housing (H) by the airfoil bearing (1) and journal bearing (75) installed at the rear of the impeller (40) with one end coupled to the hollow of the impeller (40) And the rear end is also rotatably supported by the rear bearing 80.

Hereinafter, with reference to the accompanying drawings will be described in detail with respect to the airfoil bearing 1 according to the embodiment.

2 is a perspective view of an airfoil bearing according to an embodiment of the present invention, and FIG. 3 is an exploded perspective view of an airfoil bearing according to an embodiment of the present invention.

2 and 3, the airfoil bearing 1 according to an embodiment of the present invention supports the rotation of the rotor R in both directions. At this time, a part of the rotor R passes through the airfoil bearing 1 and is connected to the rotation shaft 65 to perform rotational motion.

Here, the rotor R may include a rotor shaft R1 connected to the rotation shaft 65 of the motor, and a rotor disk R2 extending in a radial direction of the rotor shaft R1.

The airfoil bearing 1 according to an embodiment of the present invention includes first and second airfoil plates 100a and 100b and a preloading means 200.

The first and second airfoil plates 100a and 100b are disposed on both sides of the rotor R and serve to support the rotation of the rotor R in both directions.

The first and second airfoil plates 100a and 100b may include first and second bump foil plates 110a and 110b and first and second top foil plates 120a and 120b.

The first and second bump foil plates 110a and 110b may be spaced apart from each other on both sides of the rotor R. At this time, the first and second bump foil plates 110a and 110b may be elastically deformed in the axial direction of the rotor R. In this case, the first and second bump foil plates 110a and 110b may include bump foil plate portions 111a and 111b and bump foil portions 112a and 112b.

The bump foil plate portions 111a and 111b are formed in a circular disk shape. In this case, the bump foil plate portions 111a and 111b may include first members 1111a and 1111b, second members 1112a and 1112b, and third members 1113a and 1113b.

The first members 1111a and 1111b are formed in a ring shape to form a hollow through which the rotor passes.

The second members 1112a and 1112b are formed in a ring shape having a larger diameter than the first members 1111a and 1111b, and are spaced apart from the first members 1111a and 1111b in the radial direction. In this case, a plurality of first fasteners h1 may be formed in the second members 1112a and 1112b. Here, the first fastener h1 may be disposed to be spaced apart at 120° intervals based on the center of the rotor R.

The third members 1113a and 1113b are disposed radially with respect to the rotational axis of the rotor R to connect the first members 1111a and 1111b and the second members 1112a and 1112b.

The bump foil portions 112a and 112b are plural, and are radially disposed in the space between the third members 1113a and 1113b. The plurality of bump foil portions 112a and 112b are spaced apart from each other at equal intervals. The bump foil parts 112a and 112b have a trapezoidal planar shape, and have a wave shape in which a plurality of peaks and valleys are alternately connected so as to be elastically deformed in the axial direction of the rotor R.

In this case, the first and second bump foil plates 110a and 110b may be manufactured by pressing a thin metal plate.

The first and second top foil plates 120a and 120b are disposed between the first and second bump foil plates 110a and 110b and both surfaces of the rotor R, respectively. In this case, the first and second top foil plates 120a and 120b may include top foil plate portions 121a and 121b and top foil portions 122a and 122b.

The top foil plate portions 121a and 121b are formed in a circular disk shape. In this case, the top foil plate portions 121a and 121b may include fourth members 1211a and 1211b, fifth members 1212a and 1212b, and sixth members 1213a and 1213b.

The fourth members 1211a and 1211b are formed in a ring shape to form a hollow through which the rotor passes. At this time, the fourth members 1211a and 1211b are disposed to face the first members 1111a and 1111b of the bump foil plate portions 111a and 111b.

The fifth members 1212a and 1212b are formed in a ring shape having a larger diameter than the fourth members 1211a and 1211b, and are spaced apart from the fourth members 1211a and 1211b in the radial direction. Also, the fifth members 1212a and 1212b are disposed to face the second members 1112a and 1112b of the bump foil plate portions 111a and 111b. In this case, the fifth members 1212a and 1212b may have a plurality of second fasteners h2 corresponding to the first fasteners h1.

The sixth members 1213a and 1213b are disposed radially with respect to the rotational axis of the rotor, and the sixth members 1213a and 1213b connect the fourth members 1211a and 1211b and the fifth members 1212a and 1212b. At this time, the sixth members 1213a and 1213b are disposed to face the third members 1113a and 1113b of the bump foil plate portions 111a and 111b.

The top foil portions 122a and 122b are disposed between the sixth members 1213a and 1213b. One of the four sides of the top foil portions 122a and 122b is connected to the top foil plate portions 121a and 121b, and the other three sides are formed as free ends.

In this case, the first and second top foil plates 120a and 120b may be manufactured by pressing a thin metal plate.

A separation distance ratio between the rotor disk R2 and the first or second airfoil plates 100a, 100b to the axial thickness of the first or second airfoil plates 100a, 100b may be 0.1 to 0.3. . At this time, if the distance between the rotor disk R2 and the first or second airfoil plates 100a, 100b is too close, the cooling efficiency of the airfoil bearing 1 may decrease, and the rotor disk R2 and When the separation distance between the first or second airfoil plates 100a and 100b is too large, it is difficult to manage aerodynamic performance.

Figure 4 is a side cross-sectional view of an airfoil bearing according to an embodiment of the present invention, Figure 5 is a perspective view of the mesh damper shown in Figures 2 to 4;

4 and 5, the mesh damper 210 is disposed between the first and second airfoil plates 100a and 100b. In this case, both sides of the mesh damper 210 may contact the first and second top foil plates 120a and 120b.

The mesh damper 210 is disposed outside the rotor R. In this case, the mesh damper 210 may have a hollow 201 in which the rotor R is disposed. The mesh damper 210 may have a metal wire formed in a mesh shape. In addition, the mesh damper 210 may have a plurality of through holes formed by a mesh. At this time, while the rotor R rotates, air flowing around the airfoil bearing 10 may pass through the through hole of the mesh damper 210 to form turbulence.

Here, the air that has passed between the rotor disk R2 and the first airfoil plate 100a is heated with high-temperature air due to the heat of the first airfoil plate 100a. At this time, the heated air is cooled by heat exchange with the surrounding air while turbulent flow is generated by the through hole. Further, the cooled air may be sucked between the rotor disk R2 and the second airfoil plate 100b to cool the second airfoil plate 100b, thereby lowering the temperature of the entire airfoil bearing 1. Conversely, the heated air that first passed between the rotor disk R2 and the second airfoil plate 100b is cooled by turbulence, and the cooled air is transferred to the rotor disk R2 and the first airfoil plate 100a. It is also possible to cool the first airfoil plate 100a while being sucked.

At this time, when the heated air is directly sucked into the other airfoil plate while cooling the airfoil plate on one side, the air temperature is overheated and the other airfoil plate cannot be cooled or the temperature is increased. I can. The airfoil bearing according to the present invention can prevent the air from being overheated and improve the cooling efficiency of the airfoil bearing.

The mesh damper 210 may be elastically deformed in the axial direction while being pressed by the first and second airfoil plates 100a and 100b on both sides. In this case, the height H1 in the axial direction of the mesh damper 210 may be greater than the distance d1 between the first and second airfoil plates 100a and 100b. At this time, when the mesh damper 210 is disposed between the first and second airfoil plates 100a and 100b, the length in the axial direction expands and contracts to correspond to the distance of the first and second airfoil plates 100a and 100b. Can be. At this time, the stretched mesh damper 210 has an elastic restoring force and provides a preload in a direction away from the rotor R toward the first and second airfoil plates 100a and 100b. In this case, the preload pressure of the mesh damper 210 may be adjusted through the distance from the first and second airfoil plates 100a and 100b and the height in the axial direction of the mesh damper 210.

In addition, the preload pressure of the mesh damper 210 may be adjusted through the mesh density of the mesh damper 210.

The size of the inner diameter D2 of the mesh damper 210 may correspond to or larger than the outer diameter of the rotor disk R2. In addition, the outer diameter D3 of the mesh damper 210 may be formed smaller than the outer diameters of the first and second airfoil plates 100a and 100b.

The coupling means 300 couples the mesh damper 210 and the first and second airfoil plates 100a and 100b. In this case, the coupling means 300 may include first and second airfoil plates 100a and 100b and a plurality of coupling pins 310 passing through the mesh damper 210. In this case, the plurality of coupling pins 310 may be spaced apart at 120° intervals based on the center of the rotor R. In more detail, the mesh damper 210 may have a plurality of third fasteners h3 extending in the axial direction corresponding to the second fastener h2. At this time, the coupling pin 310 passes through the first fastener h1, the second fastener h2, and the third fastener h3 arranged to overlap.

The airfoil bearing according to the present invention can be manufactured by simply laminating the airfoil plate (top foil, bump foil, etc.) without welding to the rotor, and by forming a preload by elastic restoring force inside the airfoil bearing, the airfoil It can improve the operating stability and durability of the bearing.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention within the scope not departing from the spirit and scope of the present invention described in the following claims. You will understand that you can do it.

R: rotor
100a, 100b: first and second airfoil plates
110a, 110b: first and second bump foil plates
120a, 120b: first and second top foil plates
200: preload means
210: mesh damper
300: coupling means
310: coupling pin

Claims (8)

First and second airfoil plates 100a and 100b disposed on both sides of the rotor R and supporting rotation of the rotor in both directions; And
An airfoil bearing comprising a preloading means (200) for preloading the first and second airfoil plates (100a, 100b) in a direction away from the rotor (R) in an axial direction by an elastic restoring force. The method of claim 1,
The rotor (R) is a rotor shaft (R1) connected to the rotation shaft of the motor,
An airfoil bearing comprising a rotor disk (R2) extending in a radial direction of the rotor shaft (R1) and disposed between the first and second airfoil plates (100a, 100b). The method of claim 2,
The preload means 200,
An airfoil bearing including a mesh damper 210 having a plurality of through holes disposed outside the rotor disk R2. The method of claim 1,
An airfoil bearing, characterized in that the axial height (H1) of the mesh damper (210) is greater than the separation distance (d1) between the first and second airfoil plates (100a, 100b). The method of claim 4,
A separation distance ratio between the rotor disk R2 and the first or second airfoil plate 100a, 100b to the axial thickness of the first or second airfoil plate 100a, 100b is 0.1 to 0.3 Airfoil bearing. The method of claim 3,
An airfoil bearing further comprising a coupling means (300) for coupling the first and second airfoil plates (100a, 100b) and the mesh damper (210). The method of claim 6,
The coupling means 300,
An airfoil bearing comprising a plurality of coupling pins 310 penetrating the first and second airfoil plates 100a and 100b and the mesh damper 210. The method of claim 7,
The plurality of coupling pins 310 are airfoil bearings that are spaced apart at 120° intervals based on the center of the rotor (R).

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