KR20130062757A - Journal foil bearing having bump foil without corrugation and motor having the same - Google Patents

Journal foil bearing having bump foil without corrugation and motor having the same Download PDF

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Publication number
KR20130062757A
KR20130062757A KR1020110129186A KR20110129186A KR20130062757A KR 20130062757 A KR20130062757 A KR 20130062757A KR 1020110129186 A KR1020110129186 A KR 1020110129186A KR 20110129186 A KR20110129186 A KR 20110129186A KR 20130062757 A KR20130062757 A KR 20130062757A
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KR
South Korea
Prior art keywords
foil
bump
bearing
journal
holding member
Prior art date
Application number
KR1020110129186A
Other languages
Korean (ko)
Inventor
진상욱
유영준
이형주
조봉수
Original Assignee
국방과학연구소
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 국방과학연구소 filed Critical 국방과학연구소
Priority to KR1020110129186A priority Critical patent/KR20130062757A/en
Publication of KR20130062757A publication Critical patent/KR20130062757A/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C17/00—Sliding-contact bearings for exclusively rotary movement
    • F16C17/02—Sliding-contact bearings for exclusively rotary movement for radial load only
    • F16C17/024—Sliding-contact bearings for exclusively rotary movement for radial load only with flexible leaves to create hydrodynamic wedge, e.g. radial foil bearings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C27/00—Elastic or yielding bearings or bearing supports, for exclusively rotary movement
    • F16C27/02—Sliding-contact bearings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C32/00—Bearings not otherwise provided for
    • F16C32/06—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings
    • F16C32/0603—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion
    • F16C32/0614—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion the gas being supplied under pressure, e.g. aerostatic bearings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2360/00—Engines or pumps
    • F16C2360/44—Centrifugal pumps
    • F16C2360/45—Turbo-molecular pumps

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Support Of The Bearing (AREA)

Abstract

PURPOSE: A journal foil bearing with a noncorrugated bump foil and a motor with the same are provided to form the bump foil with the small difference of out-of-roundness using the noncorrugated bump foil. CONSTITUTION: A journal foil bearing comprises a holding member(110), a top foil(120), and a bump foil(130). The holding member comprises a cylindrical opening part(101) for receiving a shaft and is extended in one direction. The top foil is received in the cylindrical opening part and is formed along the inner circumference of the holding member. The bump foil without corrugation is arranged between the top foil and the holding member to surround the top foil.

Description

JOURNAL FOIL BEARING HAVING BUMP FOIL WITHOUT CORRUGATION AND MOTOR HAVING THE SAME}

The present invention relates to a journal foil bearing comprising a plate bump foil.

A bearing is a mechanical element that fixes a rotating shaft at a fixed position and rotates the shaft while supporting the weight of the shaft and the load on the shaft. Foil bearings are bearings in which a shaft is supported by a gas film formed between the top foil and the shaft without supporting the shaft in a physical contact manner such as a ball bearing or a roller bearing.

Four foil bearings because there is no physical contact during slash and burn can be applied to high-speed rotation because they have self-corrected by the eccentric element to be rotated simultaneously with the semi-permanent life. For example, it is applicable to almost all rotary machines such as compressors, turbines, blowers, turbo expanders, turbo generators, motors and the like.

 However, the structure and operation of the existing journal foil bearings are difficult to apply to a rotating shaft having a small shaft diameter and operating at high speed. The reason for this is that it is very difficult to match the roundness of the top foil and bump foil in the bearing with the axis of rotation. For example, a rotary body operating at a rotational speed of about 20 mm or less and about 100,000 rpm or more cannot be operated normally using the journal journal bearing technology.

The technical problem of the present invention has been conceived in this respect, and it is to provide a bearing having a small size including a bump foil having a small roundness difference.

In order to achieve the above object of the present invention, a foil bearing according to an embodiment of the present invention includes a retaining member, a top foil, and a bump foil. The retaining member includes a columnar opening for receiving the shaft and extends in one direction. The top foil is received in the columnar opening and is formed along an inner circumferential surface of the retaining member. The bump foil includes a bump foil that surrounds the top foil between the top foil and the holding member and is formed without wrinkles along an outer circumference thereof.

In one embodiment related to the present invention, the bump foil may be formed of a plurality of overlapping members.

In one embodiment related to the present invention, the bump foil may be formed in an open loop shape.

As an embodiment related to the present invention, one end of the top foil may be fixed to a groove formed on an inner surface of the retaining member. The groove may be disposed between two spaced ends of the bump foil.

In order to achieve the above object of the present invention, a motor according to an embodiment of the present invention includes a columnar opening for receiving a shaft and extending in one direction, the holding member is received in the columnar opening and the holding member A foil bearing having a top foil formed along an inner circumferential surface thereof and a bump foil wrapped around the top foil between the top foil and the holding member and formed without wrinkles along an outer circumference thereof, and a rotating shaft mounted and rotating in the opening. Equipped.

According to the present invention having the above configuration, it is possible to form a bump foil having a small difference in roundness, including a bump foil having no wrinkles.

In addition, by using a bump foil having a small difference in roundness, it is possible to manufacture a rotating body having a small size and capable of high speed rotation.

1 is an exploded perspective view of a journal foil bearing related to an example of the present invention.
FIG. 2 is a cross sectional view of the journal foil bearing according to the embodiment of FIG. 1; FIG.
3 is a cross-sectional view of a journal foil bearing according to another embodiment of FIG. 1.
4 is a partial cross-sectional view showing the foil bearing of the motor in which the foil bearing of FIG. 1 is installed;

EMBODIMENT OF THE INVENTION Hereinafter, the bearing which concerns on this invention is described in detail with reference to drawings. In the present specification, the same or similar reference numerals are given to different embodiments in the same or similar configurations. As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise.

1 is a perspective view of a journal foil bearing according to an example of the present invention. FIG. 2 is a cross-sectional view of the journal foil bearing according to the embodiment of FIG. 1.

1 and 2, the journal foil bearing 100 is a mechanical element that rotates while supporting a rotating shaft (not shown) through a lubricating gas film in a non-contact manner. The journal foil bearing 100 includes a holding member 110, Top foil 120, and bump foil 130.

The retaining member 110 is cylindrical to accommodate a rotating shaft, a top foil, and a bump foil. It includes an opening 101 having an annular cross section so that a rotating shaft (not shown) can be inserted. The retaining member 110 has a groove 140 formed to fix the top foil 120.

The top foil 120 is formed on an inner surface of the retaining member 110, and when the rotating shaft is mounted on the journal foil bearing 100, the top foil 120 is formed to surround the rotating shaft and has a predetermined distance from an outer circumferential surface of the rotating shaft. Spaced apart. The top foil 120 is formed to form a gas layer between the rotating shaft and the rotating shaft when the rotating shaft is rotated. The top foil 120 may be formed of stainless steel or Inconel, which is a rigid material that does not generate deformation even at a high temperature. In addition, the top foil 120 may have a thin film form and may be elastically deformable.

One end of the top foil 120 is inserted into the groove 140. However, the top foil 120 is not fixed to both ends of the top foil 140 because vibration occurs while the rotation axis rotates and thermal expansion occurs due to heating by fluid friction. That is, the one end is fixed to the groove 140, the other end is formed to be a free end to vibrate. One end fixed to the groove 140 may be a simple fitting method, or fixed or fixed by welding. In addition, a solid lubrication coating may be applied to reduce frictional force due to physical contact until a gas layer is formed between the top foil 120 and the rotating shaft 101.

The bump foil 130 is formed to surround the top foil 120. The bump foil 130 is formed of a member having a predetermined elasticity to reduce vibration of the rotating shaft. By disposing the bump foil 130, it is possible to absorb a load generated from the rotating shaft and a vibration shock.

That is, the bump foil 130 is a rigid member, and functions to damp a load in a radial direction in addition to supporting the top foil 120.

The bump foil 130 may be formed in a plate shape. That is, the wrinkle-free plate-shaped bump foil 130 is formed to surround the top foil 120. That is, the bump foil 130 and the top foil 120, and the inner surfaces of the bump foil 130 and the holding member 110 are in surface contact with each other. That is, the inner surface of the holding member 110, the bump foil 130 and the top foil 120 are arranged so that the respective surfaces abut in order.

The bump foil 130 formed in a plate shape may have a small roundness of a shape formed by a cross section of the bump foil 130 when the top foil 120 is wrapped. That is, when the shape formed by the bump foil 130 is placed between the geometric circles, the distance between the two circles can be formed small, so that the bump foil 130 can be formed as close as possible to the circle.

Therefore, it is possible to maximize the vibration reduction effect when the rotating body rotates.

In addition, the bump foil 130 may form an open loop. That is, both ends of the bump foil 130 are not connected to each other and are not fixed. That is, both ends of the bump foil 130 may be formed to be spaced apart by a predetermined distance d from the top foil 120 inserted into the groove 140.

Therefore, the bump foil 130 may vibrate when the rotation shaft rotates, and the bump foil 130 vibrates and both ends of the bump foil 130 become free ends. The separation distances (d) of both ends of the bump foil 130 are deformable at the time of vibration, thereby improving the vibration reducing effect.

Further, in the case of the bump foil wrapping the top foil while forming the corrugation, when the diameter of the rotating shaft is small, for example, when the diameter is smaller than about 20 mm, that is, the diameter D of the opening 101 is about If the top foil is to be formed on the order of 20 mm, it is difficult to form the top foil in a circle. That is, in this case, the roundness of the top foil may be large. In this case, there is no gas layer for normal operation of the journal foil bearing, making it difficult to achieve smooth rotation.

In addition, since the journal foil bearing of the present invention uses a plate-shaped bumper foil, the journal foil bearing has a higher roundness than the journal foil bearing having the corrugated bump foil and thus is applicable to high speed rotation of 100,000 rpm or more. In addition, normal operation is possible at much higher rotational speeds than conventional ball and roller bearings.

3 is a cross-sectional view of a journal foil bearing according to another embodiment of FIG. 1.

Referring to FIG. 3, the foil bearing 100 includes a retaining member 110, a top foil 120, a first bump foil 131a, and a second bump foil 131b. Except for the first and second bump foils 131a and 131b, the same components as those of FIGS. 1 and 2 may be included. Accordingly, like reference numerals refer to like elements, and description thereof will be replaced with the description of FIGS. 1 and 1.

The foil bearing 100 includes the first and second bump foils 131a and 131b. That is, in the form of a double bump foil. The first and second bump foils 131a and 131b may be formed of the same material. The first and second bump foils 131a and 131b may be formed in a plate shape and may be formed without wrinkles.

Both ends of the first and second foil bearings 131a and 131b are not fixed or attached to each other, and form a separation distance d. Both ends are formed around the groove 140. When the axis of rotation rotates, the separation distance d may vary. The first and second foil bearings 131a and 131b are disposed in surface contact with each other.

Since the load bearing capacity and the rigidity are increased due to the first and second foil bearings 131a and 131b, a higher vibration reduction effect can be expected.

4 is a partial cross-sectional view illustrating a foil bearing of a motor in which the foil bearing of FIG. 1 is installed. ,

1 and 4, the motor 200 includes a housing 210, a stator 220, a hub 240, a rotor 230, a rotation shaft 201, and a foil bearing 100.

The housing 210 forms an exterior of the motor 200. The stator 230 is fixed to the housing 200, and the rotor 220 is fixed to the hub 240. A coil (not shown) is wound around the stator 230, and the rotor 220 may be formed of a permanent magnet. Therefore, the rotor 220 is rotated outside the stator 230 by the stator 230.

Various rotating bodies may be installed on the outer surface of the hub 240. For example, in the case of a hard disk drive, a disk is loaded and fixed.

The rotating shaft 201 is inserted into the foil bearing 100. The rotating shaft 201 is disposed to be in surface contact with the top foil 120. The top foil 120 is lifted and non-contacted with respect to the rotation shaft 201 when the rotation shaft 201 is rotated by the stator 230 and the rotor 220. When the rotating shaft 201 does not rotate, it is in contact with the rotating shaft 201.

That is, when an appropriate current is applied to the coil wound around the stator 230, the rotor 220 is rotated about the stator 230. As the rotor 220 is rotated, the hub 240 rotates, and accordingly, the top foil 120 rotates. A predetermined air pressure is generated between the top foil 120 and the rotation shaft 201. Thus, the rotating shaft 201 rotates without contact with the foil bearing 100. Therefore, the rotation centers of the top foil 120 and the rotation shaft 201 may not be coincident with each other.

Although not shown in the drawings, a cooling unit for cooling the heat generated during the rotation may be further included.

The vibration generated when the rotating shaft 201 rotates is reduced by the bump foil 130.

The journal foil bearing described above is not limited to the configuration and method of the embodiments described above, but the embodiments are configured by selectively combining all or part of the embodiments so that various modifications can be made. May be

Claims (6)

A holding member extending in one direction and including a columnar opening for receiving a shaft;
A top foil accommodated in the columnar opening and formed along an inner circumferential surface of the holding member;
And a bump foil wrapped around the top foil between the top foil and the holding member and formed without wrinkles along an outer circumference thereof. The method of claim 1,
Journal face bearing, characterized in that the inner peripheral surface of the holding member and the bump foil surface bonded. The method of claim 2,
And the bump foil is formed of a plurality of overlapping members. The method of claim 2,
The bump foil is formed in the form of an open loop,
Journal foil bearing, characterized in that the distance between the spaced end of the bump foil is variable. One end of the top foil is fixed to the groove formed on the inner surface of the holding member,
And the groove is formed between two spaced ends of the bump foil. A journal foil bearing according to any one of claims 1 to 5; And
And a rotation shaft mounted to the opening to rotate.
KR1020110129186A 2011-12-05 2011-12-05 Journal foil bearing having bump foil without corrugation and motor having the same KR20130062757A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020110129186A KR20130062757A (en) 2011-12-05 2011-12-05 Journal foil bearing having bump foil without corrugation and motor having the same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020110129186A KR20130062757A (en) 2011-12-05 2011-12-05 Journal foil bearing having bump foil without corrugation and motor having the same

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Publication Number Publication Date
KR20130062757A true KR20130062757A (en) 2013-06-13

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111664169A (en) * 2020-06-22 2020-09-15 珠海格力电器股份有限公司 Elastic support assembly and radial bearing adopting same
CN112081817A (en) * 2020-09-30 2020-12-15 中车株洲电机有限公司 Radial gas foil bearing
CN113251075A (en) * 2021-06-24 2021-08-13 西北农林科技大学 Static pressure gas radial bearing with elastic wave foil support
KR102333286B1 (en) * 2021-06-09 2021-12-01 주식회사 인지니어스 The pump for the cryogenic fluid circulation with the fluid bearing

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111664169A (en) * 2020-06-22 2020-09-15 珠海格力电器股份有限公司 Elastic support assembly and radial bearing adopting same
CN111664169B (en) * 2020-06-22 2021-07-23 珠海格力电器股份有限公司 Elastic support assembly and radial bearing adopting same
CN112081817A (en) * 2020-09-30 2020-12-15 中车株洲电机有限公司 Radial gas foil bearing
KR102333286B1 (en) * 2021-06-09 2021-12-01 주식회사 인지니어스 The pump for the cryogenic fluid circulation with the fluid bearing
CN113251075A (en) * 2021-06-24 2021-08-13 西北农林科技大学 Static pressure gas radial bearing with elastic wave foil support

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