KR20230007820A - Air foil journal bearing - Google Patents

Abstract

According to the present invention, an air foil journal bearing comprises: a bearing housing having a hollow space in which a rotor is arranged and a key groove concavely formed on the inner circumferential surface thereof, and formed such that both longitudinal sides thereof are opened; bump foil provided inside the bearing housing to be formed in a circumferential direction and provided with elastic bumps of an uneven shape, wherein one end thereof is coupled to the bearing housing; a key inserted into the key groove of the bearing housing, wherein both longitudinal ends thereof are fixed on the bearing housing; and top foil provided inside the bump foil to be formed in a circumferential direction, wherein one end thereof is coupled to the key to be fixed. The air foil journal bearing can prevent the key coupled to the top foil from deflecting to the inside in a radial direction to maintain the shape of the top foil to prevent a thermal increase of the top foil and the rotor to improve durability.

Description

Air foil journal bearing {Air foil journal bearing}

The present invention is an air foil journal bearing in which air is introduced between a rotor and a foil rotating at high speed to form pressure so that the rotor is lifted from the foil and supports a radial load of the rotor. It relates to an air foil journal bearing capable of improving durability.

A bearing is a mechanical element that fixes a rotating shaft at a certain position and allows the shaft to rotate while supporting the weight of the shaft and the load applied to the shaft at the same time.

Among the bearings, the air foil bearing is a bearing that supports a load by forming pressure by introducing air, which is a viscous fluid, between the rotor and the foil in contact with the rotor at high speed.

Among these air foil bearings, air foil journal bearings are bearings configured to support radial loads of the rotor.

For example, the conventional air foil journal bearing 10 includes a housing 5 supporting a rotating rotor 4 as shown in FIGS. 1 and 2, a top foil 2 mounted along the inner surface of the housing 5, and bumps. It consists of a foil (1). In addition, one end of the top foil (2) is attached to a spacer block (key, 3) inserted into the keyway of the housing (5) by spot welding and installed inside the housing (5). The inner circumferential surface forms the bearing surface 21 . In addition, the bump foil 1 supports the top foil 2 by attaching one end to a spacer block (key 3) inserted into the keyway of the housing 5 or to the inner surface of the housing 5 by spot welding or the like. . In addition, the bump foil 1 may be integrally formed or may be divided into several pieces and installed. As shown, the bump foil may be divided into three parts (1, 1', 1") and attached to spacer blocks (3, 3', 3"), respectively.

However, as the rotor 4 rotates, friction and vibration occur between the rotor 4 and the top foil 2, and as a result, force is applied to the top foil, so that the spacer block attached to the top foil moves radially from the keyway of the housing. A key deflection phenomenon that comes out slightly inward in the direction may occur. Here, the gap between the inner circumferential surface of the top foil 2 and the outer circumferential surface of the rotor 4 is generally very small, about 0.2 mm, and the change in this gap is closely related to the temperature rise of the foils and the rotor.

That is, if the gap between the top foil and the rotor decreases due to key deflection, the temperature of the top foil and the rotor may rise and overheat, which may damage or break the top foil and rotor, reducing the durability of the airfoil journal bearing. There is a problem of deterioration and a decrease in lifespan.

KR 10-2005-0105752 A (2005.11.08.)

The present invention has been made to solve the above-described problems, and an object of the present invention is to prevent a key coupling a top foil to a keyway of a housing from sagging inward in the radial direction to maintain the shape of the top foil, thereby preventing the rotor and It is to provide an air foil journal bearing capable of preventing damage to the rotor and top foil by preventing heat rise of the top foil and improving durability accordingly.

In the air foil journal bearing of the present invention for achieving the above object, a hollow in which a rotor is disposed is formed through in the axial direction, a keyway is formed concavely on an inner circumferential surface, and a position spaced radially outward from the keyway A bearing housing having concave locking holes formed at both ends in the axial direction and a locking jaw formed between the keyway and the locking hole in the radial direction; a bump foil provided inside the bearing housing, formed in a circumferential direction, formed with concavo-convex elastic bumps, and coupled to the bearing housing; a key that is inserted into the key groove of the bearing housing, has a pair of hooks extending upward from both ends in the axial direction of the body, and is fixed with the pair of hooks caught on the hooks of the bearing housing; and a top foil provided inside the bump foil and formed in a circumferential direction, one end of which is coupled to and fixed to the key. It can be made including.

In addition, the locking hook of the key may include a pair of supports extending from both ends in the axial direction of the body; and locking protrusions protruding in directions facing each other at the free ends of the pair of supports. can include

In addition, the support may be formed of an elastic material.

In addition, an axial length of the locking protrusion of the bearing housing may correspond to a distance between a pair of supports of the key.

In addition, both ends in the axial direction of the locking jaw of the bearing housing may be formed to be spaced apart from each other in the axial direction than corresponding side surfaces of the bearing housing in the axial direction.

In addition, both sides of the locking shoulder of the bearing housing and the locking hook of the key may be formed asymmetrically in an axial direction.

In addition, the height of one side in the axial direction of the locking jaw may be greater than the height of the other side in the axial direction, and the locking hook of the key may be formed to a length corresponding to the length of the locking jaw and coupled thereto.

In addition, in the air foil journal bearing of the present invention, a hollow in which a rotor is disposed is axially penetrated, a keyway is formed concavely on an inner circumferential surface, and both sides of the bearing housing are axially spaced from the keyway outward in the radial direction. a bearing housing having a locking hole through which a locking jaw is formed between the keyway and the locking hole in a radial direction; a bump foil provided inside the bearing housing, formed in a circumferential direction, formed with concavo-convex elastic bumps, and coupled to the bearing housing; It is inserted into the keyway of the bearing housing, a connection portion extends upward from one end of the body in the axial direction, and a hook is formed extending from the connection portion toward the other end in the axial direction. key; and a top foil provided inside the bump foil and formed in a circumferential direction, one end of which is coupled to and fixed to the key; It can be made including.

In addition, the locking hook of the key may include a support extending toward the other end in the axial direction from the connection part; and a locking protrusion protruding downward from the free end of the support. can include

In addition, the support may be formed of an elastic material.

In addition, an axial length of the locking protrusion of the bearing housing may correspond to a distance between the support of the key and the locking protrusion.

In addition, both ends in the axial direction of the locking jaw of the bearing housing may be formed to be spaced apart from each other in the axial direction than corresponding side surfaces of the bearing housing in the axial direction.

In the air foil journal bearing of the present invention, the shape of the top foil is maintained by fixing the key for coupling the top foil to the keyway of the housing so that it does not droop inward in the radial direction, thereby preventing the rotor and the top foil from rising in heat. It has the advantage of improving the durability of the rotor and top foil.

In addition, there is an advantage in that it is possible to prevent mis-assembly of the top foil by forming the key asymmetrically.

1 and 2 are cross-sectional and perspective views showing a conventional air foil journal bearing.
3 and 4 are an exploded perspective view and an assembled perspective view showing an air foil journal bearing according to a first embodiment of the present invention.
5 is a partial perspective view of an air foil journal bearing according to a first embodiment of the present invention.
6 is a partial front cross-sectional view illustrating a process of coupling a key of an air foil journal bearing to a bearing housing according to a first embodiment of the present invention.
7 is a partial front sectional view showing an air foil journal bearing according to a second embodiment of the present invention.
8 is a partial front cross-sectional view showing a process of coupling a key of an air foil journal bearing to a bearing housing according to a third embodiment of the present invention.

Hereinafter, the air foil journal bearing and air foil thrust bearing of the present invention as described above will be described in detail with reference to the accompanying drawings.

<Example 1>

3 and 4 are an exploded perspective view and an assembled perspective view showing an air foil journal bearing according to the first embodiment of the present invention, and FIG. 5 is a partial perspective view of the air foil journal bearing according to the first embodiment of the present invention.

As shown, the air foil journal bearing according to the first embodiment of the present invention may largely include a bearing housing 100, a bump foil 200, a top foil 300, and a key 400.

In the bearing housing 100, a hollow 110 penetrating both side surfaces in an axial direction is formed in a central portion, and a keyway 120 communicating with the hollow 110 may be formed. The key groove 120 may be formed concavely along the longitudinal direction from the upper side of the inner circumferential surface of the bearing housing 100 in which the hollow 110 is formed to the outside in the radial direction, and the key groove 120 may be formed continuously. In addition, a locking hole 130 may be formed in the bearing housing 100, the locking hole 130 may be formed at a position spaced apart from the keyway 120 in a radial direction, and the locking hole 130 may be formed in the bearing housing It may be formed in a concave shape inward in the axial direction, respectively, on both sides in the axial direction of (100). For example, the locking hole 130 may be formed in the form of a hole penetrating both sides of the bearing housing 100 in the axial direction, as shown. In addition, the locking hole 130 may be formed in the form of a groove concave inward in the axial direction on both sides of the bearing housing 100 in the axial direction, so that the gap between the locking holes on both sides is blocked. In addition, a locking jaw 140 may be formed between the keyway 120 and the locking hole 130 in the bearing housing 100, and for example, the locking shoulder 140 is the locking hole 130 ), the remaining flesh between the keyway 120 and the locking hole 130 may be formed as the locking jaw 140.

The bump foil 200 may include a bent portion 210 and concavo-convex elastic bumps 220 extending from the bent portion 210 in a circumferential direction. The bump foil 200 is disposed inside the hollow 110 of the bearing housing 100, and the bump foil 200 has a bent portion 210 in which one end in the circumferential direction is bent outward in the radial direction is inserted into the keyway 120 can be combined In addition, the bump foil 200 may be formed in a thin plate shape, and a plurality of elastic bumps 220 convexly protruding inward in a radial direction may be spaced apart from each other along the circumferential direction. In addition, the bump foils 200 may be formed to extend in a clockwise direction based on the bent portion 210 coupled to the bearing housing 100 . In addition, the bump foils 200 may be formed in plurality so that the bump foils 200 may be arranged spaced apart from each other in the circumferential direction, or the bump foils 200 may be overlapped in two or more layers. In addition, the bump foil may be formed in various ways.

The top foil 300 may include a bent portion 310 and a load support portion 320 . A bent portion 310 provided inside the bump foil 200 and formed along the circumferential direction and having one end in the circumferential direction bent outward in the radial direction is formed so that the bent portion 310 can be inserted into the key groove 120. . In addition, the rotor 500 may be inserted and disposed inside the top foil 300, and the load support part 320 is formed as a smooth curved surface without irregularities and has an inner circumferential surface to reduce friction caused by contact during rotation of the rotor 500. A coating film may be formed with Teflon or the like so as to be. Thus, when the rotor 500 rotates inside the top foil 300, the rotor 500 is lifted to be separated from the top foil 300 by the pressure of the flowing air, and the rotor 500 rotates smoothly. It can be. In addition, the top foil 300 may extend in a counterclockwise direction based on the bent portion 310 .

The key 400 is inserted into the key groove 120 of the bearing housing 100, and the hooks formed on both sides in the axial direction are caught on the locking jaws 140 of the bearing housing 100, so that the key 400 is axially and radially It can be fixed to the bearing housing 100 without being separated. The key 400 may include a body 410 and a pair of catching hooks, and each pair of catching hooks may include a support 420 and a catching protrusion 430 . The body 410 may be formed in a rectangular plate shape having a relatively thin thickness compared to axial and radial lengths (horizontal length and vertical length). Each of the supports 420 extends from both ends in the axial direction of the body 410 upward, radially outward, and protruding protrusions 430 may protrude from free ends of the supports 420 in directions facing each other. there is. In addition, the entirety of the key 400 may be formed of an elastic material, and only the support 420, which is a part of the key 400, may be formed of an elastic material, or only the support 420 and the locking protrusion 430 may be formed of an elastic material. may be Also, the key 400 may be coupled to one side of the bent portion 310 of the top foil 300 by welding or the like, so that the key 400 and the top foil 300 may be formed as an integral assembly.

6 is a partial front cross-sectional view illustrating a process of coupling a key of an air foil journal bearing to a bearing housing according to a first embodiment of the present invention.

Referring to FIG. 6 , in a state in which the key 400 and the top foil 300 are formed as an integral assembly, the assembly is inserted into the bearing housing 100 in the axial direction, and then the key 400 is inserted in the radial direction. After the support 420 of the catching hook opens outward in the axial direction by being pushed upward, the catching protrusion 430 can be assembled to be inserted into the catching hole 130 to be caught by restoring its original shape.

Therefore, the air foil journal bearing of the present invention can be easily fixed to the bearing housing so that the key connecting the top foil to the keyway of the housing does not droop inward in the radial direction. Accordingly, the key and the top foil may be fixed to the bearing housing to maintain the shape of the top foil, and as a result, heat rise of the rotor and the top foil may be prevented, thereby improving durability of the rotor and the top foil.

In addition, the axial length of the locking protrusion 140 of the bearing housing 100 may be formed to correspond to the distance between the pair of supports 420 of the key 400 . That is, the distance between the pair of supports 420 is greater than or equal to the axial length of the locking jaw 140 so that the locking jaw 140 can be well inserted between the pair of supporters 420 of the key 400. can be formed

In addition, both ends in the axial direction of the locking protrusion 140 of the bearing housing 100 may be formed at positions spaced apart in the axial direction from the side surfaces of the bearing housing 100 in the axial direction. That is, the locking jaw 140 may be formed in a shape that is recessed inward from the side surface in the axial direction of the bearing housing 100 . Thus, the body 410 of the key 400 and the pair of supports 420 can be formed so as not to protrude outward from the axial side of the bearing housing 100 .

<Example 2>

7 is a partial front sectional view showing an air foil journal bearing according to a second embodiment of the present invention.

As shown, in the air foil journal bearing according to the second embodiment of the present invention, both sides in the axial direction of the locking shoulder 140 of the bearing housing 100 and both sides in the axial direction of the locking hook of the key 400 are formed asymmetrically. can For example, the height H1 of one side in the axial direction of the locking jaw 140 is formed in a stepped shape larger than the height H2 of the other side in the axial direction, and the locking hook of the key 400 corresponds to the locking jaw 140. When the key and the top foil are integrally coupled to the bearing housing 100 by being formed in a length, it is possible to prevent misassembly in which the direction of the top foil is incorrectly assembled.

In addition, the rest of the configuration may be formed in the same manner as in the first embodiment described above.

In addition, in the second embodiment of the present invention, the key and top foil are fixed to the bearing housing so that the shape of the top foil can be maintained, and as a result, heat rise of the rotor and top foil is prevented to improve durability of the rotor and top foil. can make it

<Example 3>

8 is a partial front cross-sectional view showing a process of coupling a key of an air foil journal bearing to a bearing housing according to a third embodiment of the present invention.

As shown, the air foil journal bearing according to the third embodiment of the present invention may have locking holes 130 penetrating both side surfaces of the bearing housing 100 in the axial direction. In addition, the key 400 may have a connecting portion 440 extending upward from one end of the body in an axial direction and a hook hook extending from an end of the connecting portion 440 toward the other end in the axial direction. In addition, the catching hook may include a support 450 and a catching protrusion 460, and the support 450 extends from the end of the connecting portion 440 to the other end in the axial direction and moves downward from the other end of the support 450. A locking protrusion 460 may protrude. Thus, in a state where the top foil 300 and the key 400 are integrally coupled, the top foil 300 and the key 400 are pushed into the bearing housing 100 in the axial direction so that the support 450 bends upward and then returns to its original state. The shape is restored to the state so that the support 450 and the locking protrusion 460 can be caught and fixed to the locking jaw 140 .

In addition, the rest of the configuration may be formed in the same manner as in the first embodiment described above.

In addition, in the third embodiment of the present invention, the key and top foil are fixed to the bearing housing so that the shape of the top foil can be maintained, and as a result, heat rise of the rotor and top foil is prevented to improve durability of the rotor and top foil. can make it In addition, in the third embodiment of the present invention, when the key 400 is also axially inserted into the bearing housing 100 in the same axial direction as the bump foil 200 and the top foil 300 are inserted, coupling and fixing are completed. Therefore, it can be easily assembled.

The present invention is not limited to the above embodiments, and the scope of application is diverse, and anyone having ordinary knowledge in the field to which the present invention belongs without departing from the gist of the present invention claimed in the claims Of course, various modifications are possible.

100: bearing housing
110: hollow 120: keyway
130: catching hole 140: catching jaw
200: bump foil
210: bent portion 220: elastic bump
300: top foil
310: bending part 320: load support part
400: key
410: body 420: support
430: snag 440: connection
450: support 460: snag
500: rotor

Claims (12)

The hollow in which the rotor is disposed is formed through in the axial direction, a keyway is formed concavely on the inner circumferential surface, and locking holes are formed concavely at both ends in the axial direction spaced apart from the keyway in the radial direction outwardly so that the keyway and the keyway are formed in the radial direction. a bearing housing with a locking jaw formed between the locking holes;
a bump foil provided inside the bearing housing, formed in a circumferential direction, formed with concavo-convex elastic bumps, and coupled to the bearing housing;
a key that is inserted into the key groove of the bearing housing, has a pair of hooks extending upward from both ends in the axial direction of the body, and is fixed with the pair of hooks caught on the hooks of the bearing housing; and
a top foil provided inside the bump foil and formed in a circumferential direction, one end of which is coupled to and fixed to the key;
An air foil journal bearing comprising a.
According to claim 1,
The locking hook of the key,
a pair of supports extending from both ends of the body in the axial direction; and
locking protrusions protruding from the free ends of the pair of supports in directions facing each other; An air foil journal bearing comprising a.
According to claim 2,
The air foil journal bearing, characterized in that the support is formed of an elastic material.
According to claim 2,
An air foil journal bearing, characterized in that the axial length of the locking jaw of the bearing housing is formed to correspond to the distance between the pair of supports of the key.
According to claim 4,
Air foil journal bearings, characterized in that the both ends in the axial direction of the locking jaw of the bearing housing are formed to be spaced apart from the corresponding axial side surfaces of the bearing housing in the axial direction.
According to claim 2,
The air foil journal bearing, characterized in that the locking jaw of the bearing housing and the locking hook of the key are formed asymmetrically on both sides in the axial direction.
According to claim 6,
The locking jaw is formed so that the height of one side in the axial direction is greater than the height of the other side in the axial direction,
The air foil journal bearing, characterized in that the locking hook of the key is formed to a length corresponding to the locking jaw and coupled.
The hollow in which the rotor is disposed is formed through in the axial direction, a keyway is formed concavely on the inner circumferential surface, and a locking hole is formed that penetrates both side surfaces of the bearing housing in the axial direction at a position spaced apart from the keyway in the radial direction outward to form a radius a bearing housing having a locking jaw formed between the keyway and the locking hole in the direction;
a bump foil provided inside the bearing housing, formed in a circumferential direction, formed with concavo-convex elastic bumps, and coupled to the bearing housing;
It is inserted into the keyway of the bearing housing, a connection part extends upward from one end of the body in the axial direction, and a hook is formed extending from the connection part toward the other end in the axial direction. key; and
a top foil provided inside the bump foil and formed in a circumferential direction, one end of which is coupled to and fixed to the key;
An air foil journal bearing comprising a.
According to claim 8,
The locking hook of the key,
a support formed extending toward the other end in the axial direction from the connecting portion; and
a locking protrusion protruding downward from the free end of the support; An air foil journal bearing comprising a.
According to claim 9,
The air foil journal bearing, characterized in that the support is formed of an elastic material.
According to claim 9,
An air foil journal bearing, characterized in that the axial length of the locking jaw of the bearing housing is formed to correspond to the distance between the support of the key and the locking protrusion.
According to claim 11,
Air foil journal bearings, characterized in that the both ends in the axial direction of the locking jaw of the bearing housing are formed to be spaced apart from the corresponding axial side surfaces of the bearing housing in the axial direction.

Images