CN111188686B - Double-ball bearing supporting structure for preventing light load from slipping - Google Patents
Double-ball bearing supporting structure for preventing light load from slipping Download PDFInfo
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- CN111188686B CN111188686B CN202010061980.1A CN202010061980A CN111188686B CN 111188686 B CN111188686 B CN 111188686B CN 202010061980 A CN202010061980 A CN 202010061980A CN 111188686 B CN111188686 B CN 111188686B
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- bearing
- axial
- load
- front bearing
- double
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
- F02C7/00—Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants
- F02C7/06—Arrangements of bearings; Lubricating
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/05—Shafts or bearings, or assemblies thereof, specially adapted for elastic fluid pumps
- F04D29/056—Bearings
- F04D29/059—Roller bearings
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
- F04D29/661—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps
- F04D29/668—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps damping or preventing mechanical vibrations
Abstract
The invention discloses a double-ball bearing supporting structure for preventing light load from slipping, which is used for rear support of an engine fan and is used for reducing deflection and vibration in the operation process of a large-size fan and improving the reliability of an engine. In the prior art, a mode of combining a roller bearing with a ball bearing is generally adopted, however, the roller bearing which can only bear radial load under the combination has the risk of slipping under light load. According to the double-ball bearing combined supporting structure provided by the invention, the axial load of the front bearing is provided in an oil pressure mode, the axial load applied by oil pressure is always borne by the front bearing through controlling the axial gaps on the two sides of the outer ring of the front bearing, the resultant force of the axial force and the oil pressure pretightening force in the running process of an engine is always borne by the rear bearing, and the risk of light-load slipping of double-bearing supporting is reduced.
Description
Technical Field
The invention relates to the technical field of aircraft engines, in particular to a double-ball bearing supporting structure for preventing light-load slipping, which can be used as a rear support of an engine fan rotor.
Background
In order to seek higher economy for civil aircraft engines, the bypass ratio has been increasing and the fan has become the largest component in the engine rotor. In order to ensure good rotor dynamics characteristic of an engine, the fan rear support mostly adopts a double-bearing structural layout for reducing deflection and vibration in the operation process of a large-size fan. The existing fan rear double-bearing support structure generally adopts a mode of combining a rolling rod bearing with a ball bearing, such as a CFM56 engine, however, in the full flight envelope range of the engine, the change of temperature can affect the value of the radial play of the bearing, and the rolling rod bearing which can only bear the radial load can generate light-load slipping due to overlarge radial play.
The solution to the light-load slipping of the bearing is to ensure that the bearing always bears a proper axial/radial load, but how to ensure the distribution of the loads of the two bearings in the double-bearing solution is a problem to be solved urgently on how to structurally realize the function on the premise of completing the double-bearing layout.
Disclosure of Invention
Aiming at the technical problems in the prior art, the invention provides a double-ball bearing supporting structure for preventing light-load slipping, which is suitable for the rear support of an engine fan rotor.
In order to achieve the aim, the invention adopts the technical scheme that:
a double-ball bearing supporting structure for preventing light load from slipping is suitable for the rear support of an engine fan rotor, the fan rotor is fixedly arranged at the front end of an engine low-pressure rotor shaft, the engine low-pressure rotor shaft is rotatably supported on an inner casing of an engine through a double-ball bearing supporting structure formed by a front bearing and a rear bearing, the front end of the inner casing is at least provided with a front bearing seat and a rear bearing seat, outer rings of the front bearing and the rear bearing are respectively arranged on the front bearing seat and the rear bearing seat, inner rings of the front bearing and the rear bearing are respectively arranged on the engine low-pressure rotor shaft, and a distance ring is also arranged between the inner rings of the front bearing and the rear bearing,
the outer ring of the rear bearing is arranged on the rear bearing seat in an axially immovable mode, so that the rear bearing cannot slide under light load;
axial gaps are arranged on the left side and the right side of an outer ring of the front bearing respectively, and the axial gaps on the left side and the right side are larger than the difference value of the axial clearances of the front bearing and the rear bearing; and the right end face of the outer ring of the front bearing is provided with an oil pressure structure, and a set pre-load axial load is applied to the right end face of the outer ring of the front bearing through the oil pressure structure, so that the front bearing cannot slip under a light load.
Preferably, the outer ring of the rear bearing is formed on the rear bearing seat in an integrated manner.
Preferably, the outer ring of the rear bearing is arranged on the rear bearing seat through an axial limiting device.
Preferably, the oil pressure structure includes an annular biography power piece and a high pressure oil feed pipe at least, annular biography power piece sets up in the front axle bearing seat, the outer terminal surface butt in the left side of annular biography power piece is in on the right-hand member face of front bearing's outer loop, just the right side wall of annular biography power piece with form a confined lubricating oil chamber between the wall of front axle bearing seat, the end of high pressure oil feed pipe with lubricating oil chamber intercommunication, through high pressure oil feed pipe to lubricating oil chamber fills high-pressure lubricating oil, makes annular biography power piece is right the front bearing is applyed pre-load axial load.
Further, the pre-load of the front bearing is provided by high-pressure lubricating oil, and the pre-load of the front bearing is adjusted by adjusting the lubricating oil pressure of the high-pressure oil supply pipe and the size of the acting surface of the annular force transmission member.
Preferably, the pre-axial load is loaded in the same direction as the axial force of the low pressure rotor shaft of the engine, the pre-axial load preferably being greater than 300N.
Preferably, the front bearing and the rear bearing are both three-point contact ball bearings.
Further, in order to guarantee assembly, the inner rings of the front bearing and the rear bearing are divided into two halves, and the left half bearing is provided with a pulling and unloading groove for detaching the inner ring of the bearing.
Preferably, the inner ring inner diameter of the rear bearing is preferably larger than the inner ring inner diameter of the front bearing.
Preferably, axial gaps on the left side and the right side of the outer ring of the front bearing are all 0.5-1 mm, and the axial gaps are larger than the difference value of axial clearances of the two bearings.
Preferably, the front bearing outer ring is further provided with a squeeze film structure to improve the rotor dynamic characteristics of the low-pressure rotor shaft of the low-pressure engine.
In the double-ball bearing support structure for preventing the light-load slipping, the rear bearing is a bearing for bearing the axial force of the low-pressure rotor shaft of the engine, the bearing capacity is higher than that of the front bearing, and the front bearing always bears the axial load preloaded by the high-pressure lubricating oil no matter how the magnitude and the direction of the axial force of the low-pressure rotor shaft of the engine are changed.
Preferably, the cooling lubrication, the squeeze film and the pre-load of the front bearing and the rear bearing are all the same lubricating oil source.
The invention relates to a double-ball bearing supporting structure for preventing light load from slipping, which has the working principle that:
the rear bearing is characterized in that the outer ring of the rear bearing is arranged on the rear bearing seat in an axially immovable mode, axial gaps are arranged on the left side and the right side of the outer ring of the front bearing respectively, the axial gaps on the left side and the right side are larger than the difference value of the axial clearances of the front bearing and the rear bearing, an oil pressure structure is arranged on the right end face of the outer ring of the front bearing, and a set pre-loading axial load is applied to the right end face of the outer ring of the front bearing through the oil pressure structure. Because of the gap in the left end face of the outer ring of the front bearing, the force of the oil preload will be transmitted as the outer ring of the front bearing → the rolling elements of the front bearing → the inner ring of the rear bearing → the rolling elements of the rear bearing → the outer ring of the rear bearing. When the engine starts to operate, the axial force of the low-pressure rotor of the engine acts on the low-pressure rotor shaft of the engine, and because the outer ring of the rear bearing is axially limited, the axial movement of the outer ring of the front bearing cannot be larger than the difference value of the axial clearances of the two bearings no matter the axial force faces forwards or backwards, the gaps on the two sides of the outer ring of the front bearing are larger than the difference value of the axial clearances of the two bearings, and the outer ring of the front bearing only bears the axial force generated by the oil pressure in the lubricating oil cavity all the time. The axial force of the preloading depends on the pressure of the lubricating oil and the size of the stress surface of the annular force transmission part, and is independent of other factors, so that the front bearing can always bear the set axial load without light-load slipping. The rear bearing bears the resultant force of the axial force and the preloading force of the low-pressure rotor, and the light-load slip can not occur.
Compared with the prior art, the double-ball bearing supporting structure for preventing light load slipping has the following remarkable technical effects: the double-ball bearing supporting structure for preventing light-load slipping is suitable for the rear support of a fan rotor of an engine, provides the axial load of the outer ring of the front bearing in an oil pressure mode, can realize pre-loading on the front bearing through oil pressure on the premise of reducing fan vibration and deflection, ensures that the axial force of the low-pressure rotor always acts on the rear bearing through controlling the axial gaps on the two sides of the outer ring of the front bearing, and reduces the risk of light-load slipping of the double-ball bearing supporting.
Drawings
FIG. 1 is a schematic view of a dual ball bearing support structure for preventing light load slippage in accordance with the present invention;
fig. 2 is a partially enlarged view of fig. 1.
Detailed Description
In order to make the implementation objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be described in more detail below with reference to the accompanying drawings in the embodiments of the present invention. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, but not all embodiments of the invention. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. The structure and technical scheme of the present invention are further described in detail with reference to the accompanying drawings, and an embodiment of the present invention is provided.
As shown in fig. 1, the double ball bearing support structure for preventing a light load slip of the present invention is suitable for rear support of an engine fan rotor 3. The engine fan rotor 3 is characterized by a large size and weight, and the rear support is a double ball bearing support structure as shown in the figure to increase the axial span of the support. The engine low-pressure rotor shaft 8 is rotatably supported on an inner casing of the engine through a double-ball bearing supporting structure formed by a front bearing 1 and a rear bearing 2, the front end of the inner casing is at least provided with a front bearing seat 6 and a rear bearing seat 7, the outer rings of the front bearing 1 and the rear bearing 2 are respectively arranged on the front bearing seat 6 and the rear bearing seat 7, the inner rings of the front bearing 1 and the rear bearing 2 are respectively arranged on the engine low-pressure rotor shaft 8, and a distance ring 9 is further arranged between the inner rings of the front bearing 1 and the rear bearing 2.
Specifically, the outer ring of the front bearing 1 is arranged on a bearing seat 6, the left side of the outer ring is provided with an axial gap of 0.5-1 mm, the right side of the outer ring is provided with an annular force transmission piece 10, the right side of the annular force transmission piece 10 is provided with an axial gap of 0.5-1 mm, and the gap is larger than the difference of the axial clearances of the two bearings; the outer ring of the rear bearing 2 and the bearing seat 7 are designed integrally, so that the outer ring cannot move axially; the inner rings of the front bearing 1 and the front bearing 2 are arranged on a low-pressure rotor shaft 8 of the engine, and the axial relative position of the inner rings is controlled by the size of a distance ring 9; the oil supply pipe 5 is filled with high-pressure lubricating oil supplied by an external lubricating oil pump, the lubricating oil flows into the lubricating oil cavity 4, the lubricating oil cavity 4 consists of a bearing seat 6 and an annular force transmission part 10, the high-pressure lubricating oil in the lubricating oil cavity 4 generates axial force on the right end surface of the annular force transmission part 10 and transmits the axial force to the outer ring of the front bearing 1, and because the left end surface of the outer ring of the front bearing 1 is provided with a gap, the force preloaded by the lubricating oil is transmitted according to the outer ring of the front bearing 1 → the rolling bodies of the front bearing 1 → the inner ring of the rear bearing 2 → the rolling bodies of the rear bearing 2 → the outer ring (bearing seat 7. When the engine starts to operate, the axial force of the low-pressure rotor of the engine acts on the low-pressure rotor shaft 8 of the engine, and because the outer ring of the rear bearing 2 is axially limited, the axial movement of the outer ring of the front bearing 1 cannot be larger than the difference value of the axial clearances of the two bearings no matter the axial force faces forwards or backwards, the gaps on the two sides of the outer ring of the front bearing 1 are larger than the difference value of the axial clearances of the two bearings, and the outer ring of the front bearing 1 only bears the axial force generated by the oil pressure in the oil cavity all the time. The axial force of the preload depends on the pressure of the lubricating oil and the size of the stress surface of the annular force transmission member 10, and is independent of other factors, so that the front bearing 1 can always bear the set axial load without light-load slipping. The rear bearing 2 bears the resultant force of the axial force and the preloading force of the low-pressure rotor, and the light-load slip can not occur.
It should be noted that the specific embodiments described in the present specification may differ in the shape of the components, the names of the components, and the like. All equivalent or simple changes of the structure, the characteristics and the principle of the invention which are described in the patent conception of the invention are included in the protection scope of the patent of the invention. Various modifications, additions and substitutions for the specific embodiments described may be made by those skilled in the art without departing from the scope of the invention as defined in the accompanying claims.
Claims (10)
1. A double-ball bearing supporting structure for preventing light load from slipping is suitable for the rear support of an engine fan rotor, the fan rotor is fixedly arranged at the front end of an engine low-pressure rotor shaft, the engine low-pressure rotor shaft is rotatably supported on an inner casing of an engine through a double-ball bearing supporting structure formed by a front bearing and a rear bearing, the front end of the inner casing is at least provided with a front bearing seat and a rear bearing seat, outer rings of the front bearing and the rear bearing are respectively arranged on the front bearing seat and the rear bearing seat, inner rings of the front bearing and the rear bearing are respectively arranged on the engine low-pressure rotor shaft, and a distance ring is also arranged between the inner rings of the front bearing and the rear bearing,
the outer ring of the rear bearing is arranged on the rear bearing seat in an axially immovable mode, so that the rear bearing cannot slide under light load;
axial gaps are arranged on the left side and the right side of an outer ring of the front bearing respectively, and the axial gaps on the left side and the right side are larger than the difference value of the axial clearances of the front bearing and the rear bearing; and the right end face of the outer ring of the front bearing is provided with an oil pressure structure, and a set pre-axial load is applied to the right end face of the outer ring of the front bearing through the oil pressure structure, and the pre-axial load is transmitted according to the path from the outer ring of the front bearing → the rolling body of the front bearing → the inner ring of the rear bearing → the rolling body of the rear bearing → the outer ring of the rear bearing, so that the outer ring of the front bearing always only bears the pre-axial load, the light-load slip cannot occur, and the axial force of the low-pressure rotor shaft always acts on the rear bearing.
2. The double ball bearing support structure for preventing a slip under a light load according to claim 1, wherein an outer ring of the rear bearing is formed on the rear bearing housing in an integrated manner.
3. The double ball bearing support structure of claim 1, wherein the outer race of the rear bearing is disposed on the rear bearing seat by an axial stop.
4. The double-ball bearing support structure for preventing the light-load slipping as claimed in claim 1, wherein the oil pressure structure at least includes an annular force transmission member and a high-pressure oil supply pipe, the annular force transmission member is disposed in the front bearing seat, the outer end surface of the left side of the annular force transmission member abuts against the right end surface of the outer ring of the front bearing, a closed oil sliding cavity is formed between the right side wall surface of the annular force transmission member and the wall surface of the front bearing seat, the end of the high-pressure oil supply pipe is communicated with the oil sliding cavity, and the high-pressure oil supply pipe fills the oil sliding cavity with high-pressure oil so that the annular force transmission member applies the pre-load to the front bearing.
5. The double ball bearing support structure for preventing light load slip according to claim 4, wherein the pre-axial load of the front bearing is provided by high-pressure oil, and the pre-axial load of the front bearing is adjusted by adjusting the oil pressure of the high-pressure oil supply pipe and the size of the action surface of the annular force transmission member.
6. The double ball bearing support structure of preventing a light load slip of claim 1, wherein the pre-axial load is loaded in the same direction as the axial force of the low pressure rotor shaft of the engine, and the pre-axial load is greater than 300N.
7. The double-ball bearing support structure for preventing a light load slip according to claim 1, wherein the front bearing and the rear bearing are both three-point contact ball bearings.
8. The double-ball bearing support structure for preventing the light load from slipping as claimed in claim 7, wherein the inner rings of the front and rear bearings are divided into halves for ensuring the assembly, and the left half bearing is provided with a pull-out groove for dividing the inner ring of the bearing.
9. The double ball bearing support structure for preventing slippage under light loads according to claim 1, wherein an inner ring inner diameter of the rear bearing is larger than an inner ring inner diameter of the front bearing.
10. The double-ball bearing support structure for preventing the light-load slip according to claim 1, wherein the axial gaps on the left side and the right side of the outer ring of the front bearing are both 0.5-1 mm, and the axial gap is larger than the difference of the axial play of the two bearings; and the front bearing outer ring is also provided with a squeeze oil film structure so as to improve the rotor dynamic characteristic of the low-pressure rotor shaft of the engine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010061980.1A CN111188686B (en) | 2020-01-19 | 2020-01-19 | Double-ball bearing supporting structure for preventing light load from slipping |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010061980.1A CN111188686B (en) | 2020-01-19 | 2020-01-19 | Double-ball bearing supporting structure for preventing light load from slipping |
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| Publication Number | Publication Date |
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| CN111188686A CN111188686A (en) | 2020-05-22 |
| CN111188686B true CN111188686B (en) | 2021-03-30 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202010061980.1A Active CN111188686B (en) | 2020-01-19 | 2020-01-19 | Double-ball bearing supporting structure for preventing light load from slipping |
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3909085A (en) * | 1973-09-08 | 1975-09-30 | Rolls Royce 1971 Ltd | Preloaded bearings |
| CN102979625A (en) * | 2012-11-06 | 2013-03-20 | 中国航空工业集团公司沈阳发动机设计研究所 | Structure for aviation gas turbine rotor supporting point ball bearing axial pre-load |
| CN104005797A (en) * | 2014-06-04 | 2014-08-27 | 中国航空动力机械研究所 | Gas turbine rotor supporting mechanism and gas turbine with same |
| JP2015007451A (en) * | 2013-06-25 | 2015-01-15 | 日本精工株式会社 | Rolling bearing device |
| CN105822366A (en) * | 2016-04-20 | 2016-08-03 | 中国科学院工程热物理研究所 | Low-pressure rotor supporting structure of engine with fusing design |
| CN205714304U (en) * | 2016-04-20 | 2016-11-23 | 中国科学院工程热物理研究所 | A kind of electromotor low pressure rotor supporting structure |
| CN109281944A (en) * | 2018-10-19 | 2019-01-29 | 中国科学院工程热物理研究所 | The axial force pre-load arrangement of deep groove ball bearing in a kind of engine rotor fulcrum |
-
2020
- 2020-01-19 CN CN202010061980.1A patent/CN111188686B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3909085A (en) * | 1973-09-08 | 1975-09-30 | Rolls Royce 1971 Ltd | Preloaded bearings |
| CN102979625A (en) * | 2012-11-06 | 2013-03-20 | 中国航空工业集团公司沈阳发动机设计研究所 | Structure for aviation gas turbine rotor supporting point ball bearing axial pre-load |
| JP2015007451A (en) * | 2013-06-25 | 2015-01-15 | 日本精工株式会社 | Rolling bearing device |
| CN104005797A (en) * | 2014-06-04 | 2014-08-27 | 中国航空动力机械研究所 | Gas turbine rotor supporting mechanism and gas turbine with same |
| CN105822366A (en) * | 2016-04-20 | 2016-08-03 | 中国科学院工程热物理研究所 | Low-pressure rotor supporting structure of engine with fusing design |
| CN205714304U (en) * | 2016-04-20 | 2016-11-23 | 中国科学院工程热物理研究所 | A kind of electromotor low pressure rotor supporting structure |
| CN109281944A (en) * | 2018-10-19 | 2019-01-29 | 中国科学院工程热物理研究所 | The axial force pre-load arrangement of deep groove ball bearing in a kind of engine rotor fulcrum |
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| CN111188686A (en) | 2020-05-22 |
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