JPH0544723A - Bearing device - Google Patents

Abstract

PURPOSE:To effectively damp vibration in different directions generated on a rotating shaft. CONSTITUTION:This bearing device is provided with a bearing 12 supporting a rotating shaft 11, a supporting member 14 supporting the bearing 12 in a bearing housing 13, a fluid membrane damper part 16 formed between the supporting member 14 and the bearing housing 13, electrodes 18, 20 oppositely provided on the outer circumferential face of the supporting member 14 and the inner circumferential face of the bearing housing 13, and electroviscous fluid or liquid crystal supplied in the fluid membrane damper part 16. Either of these electrodes 18, 20 is divided, so as to control voltage applied between the electrodes according to the vibrating direction of the rotating shaft 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device capable of damping the vibration of a rotating shaft in various devices having a rotating body.

[0002]

2. Description of the Related Art Conventionally, as a bearing device for supporting a rotating shaft, a bearing for supporting the rotating shaft is supported in a bearing housing,
A fluid film damper is provided between the bearing housing and the bearing,
There is known a device that supplies fluid to the fluid film damper portion to damp vibrations transmitted from the rotary shaft to the bearing housing by a squeeze effect of the fluid film of the fluid film damper portion (for example, Japanese Patent Laid-Open Publication No. Sho. 54-96650 and JP-A-57-1822).

However, in the above conventional bearing device, the vibration damping characteristic of the fluid film damper is determined by the viscosity coefficient of oil, the axial length of the fluid film damper, and the clearance, so that the oil temperature varies. Alternatively, if the axial length and the gap of the fluid film damper change due to manufacturing errors, there is a drawback that the desired vibration damping effect cannot be obtained.

To overcome this drawback, the applicant has
By supplying an electrorheological fluid to the fluid film damper section and controlling the viscosity of this electrorheological fluid with a voltage, a bearing device capable of constantly providing an optimum vibration damping force for various vibration modes is disclosed. No. 288612 and Japanese Patent Application Laid-Open No. 1-288613.

[0005]

By the way, when the rotating shaft is rotated, the natural frequencies of the rotating shaft in the vertical direction and in the horizontal direction are slightly different from each other. Directional resonances will occur separately.

However, in the bearing device proposed by the applicant of the present invention, even if the damping force is adjusted by controlling the viscosity of the electrorheological fluid by the voltage when vibration in one direction occurs on the rotating shaft, Since the same voltage is applied to the entire circumference of the fluid film damper part, there is a problem that the vibration is not effectively attenuated in other directions but is also amplified in some cases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a bearing device capable of effectively attenuating vibrations of a rotating shaft in different directions.

[0008]

To this end, the bearing device of the present invention comprises a bearing 12 for supporting the rotating shaft 11, a support member 14 for supporting the bearing 12 in a bearing housing 13, a support member 14 and a bearing housing 13. A fluid film damper portion 16 formed between the electrode 18 and the outer peripheral surface of the support member 14 and the inner peripheral surface of the bearing housing 13,
20 and an electrorheological fluid supplied into the fluid film damper section 16, one of the electrodes 18, 20 is divided, and the voltage applied between the electrodes is controlled by the vibration direction of the rotating shaft. It is characterized by enabling. Liquid crystal may be used instead of the electrorheological fluid, and in that case, one of the electrodes may not be divided. It should be noted that the numbers added to the above configuration are for comparison with the drawings for easy understanding, and the configuration of the present invention is not limited thereby.

[0009]

In the present invention, when a voltage is applied between the opposing electrodes of the fluid film damper portion, an electric field is formed which is orthogonal to the flow of the electrorheological fluid toward both axial ends of the fluid film damper portion. Since the viscosity of the rotating shaft increases, the vibration of the rotating shaft can be effectively reduced by controlling the viscosity of the fluid, and one electrode is divided and applied to the electrode according to the rotating direction of the rotating shaft. By controlling the voltage, the viscosity of the fluid can be directionally controlled,
It is possible to effectively damp vibrations of the rotating shaft in different directions. Further, when liquid crystal is used instead of the electrorheological fluid, the state such as the direction and arrangement of the liquid crystal molecules sandwiched between the electrodes 7 and 8 changes, and the viscosity of the liquid crystal increases or decreases.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows one embodiment of the bearing device of the present invention.
Is a cross-sectional view, and FIG. B is a side view seen from the left in FIG.

1 and 2, the bearing device 10 is shown.
Has a bearing 12 that rotatably supports the rotating shaft 11, a bearing housing 13, and a support member 14 that supports the bearing 12 in the bearing housing 13. The bearing 12 includes an outer race 12A, a ball bearing 12B and an inner race 12C, and the support member 14 includes a tubular portion 14A.
And a flange portion 14B, and is made of an electrically insulating material. The rotary shaft 11 is press-fitted and fixed to the inner race 12C of the bearing 12, and the outer race 12A
By fixing the tubular portion 14A of the support member 14 to the bearing housing 13 by fixing the flange portion 14B of the support member 14 to the bearing housing 13 with the bolts 15, the rotary shaft 11, the bearing 12, and the support member 14 are fixed inside the bearing housing 13. Is fixed on the same axis so that the gap of the fluid film damper portion 16 described later becomes constant.

A fluid film damper portion 16 is formed between the bearing housing 13 and the flange portion 14B of the support member 14, and a fluid supply passage 17 communicating with the fluid film damper portion 16 is formed in the bearing housing 13. Has been formed. A ring-shaped electrode 18 is provided on the outer peripheral surface of the cylindrical portion 14A of the support member 14, and an electrically insulating member 19 is provided on the inner peripheral surface of the bearing housing 13 facing the electrode 18. An electrode 20 is provided. Then, the electrorheological fluid is supplied from the fluid supply passage 17 into the fluid film damper portion 16, and is discharged to the outside from both axial end portions of the fluid film damper portion 16.

FIG. 2 is a schematic view showing an arrangement example of the electrodes 18 and 20. One electrode 18 is a ring-shaped integrally formed electrode, while the other electrode 2 is
In No. 0, the electrodes 20A, 20B, 20C, 20D are arranged by being divided into four in the circumferential direction. The electrode may be divided into four or more, and the electrode 18 may be divided into two or more electrodes.
The 0 may be integrally formed in a ring shape.

FIG. 3 shows an example of a method for controlling the voltage applied to the electrodes. The detection signals of the vertical vibration sensor 21 and the horizontal vibration sensor 22 are input to the electronic control unit 23, and the control stored in advance here. Data is compared and processed,
Voltages that effectively attenuate the vibrations in the respective directions are applied to the electrodes 20A, 20C in the vertical direction and the electrodes 20B, 20D in the horizontal direction with respect to the electrode 18. In addition, when the number of electrodes 20 is increased in FIG. 2, vibration in a predetermined direction is calculated from detection signals of the vertical vibration sensor 21 and the horizontal vibration sensor 22, and a voltage is applied to the electrodes in the corresponding direction. By doing so, it is possible to effectively damp vibrations of the rotating shaft in all directions.

Next, the operation of the present invention having the above structure will be described. The electrorheological fluid supplied from the fluid supply path 17 into the fluid film damper portion 16 forms a liquid film on the fluid film damper portion 16, and the rotating shaft 11 to the bearing 12 and the support member 1
4. After the vibration transmitted to the bearing housing 13 is attenuated by the squeeze effect, it is discharged to the outside from both axial end portions of the fluid film damper portion 16. At this time, the electrode 18,
When a voltage is applied between the electrodes 20A, 20B, 20C, and 20D, an electric field that is orthogonal to the flow of the electrorheological fluid toward both ends of the fluid film damper portion 16 in the axial direction is formed. As a result, the viscosity of the electrorheological fluid increases. Therefore, by controlling the viscosity of the fluid, the vibration of the rotating shaft 11 can be effectively reduced, and, as described with reference to FIG. By controlling the voltage applied to the electrodes, the viscosity of the fluid can be directionally controlled, and the vibrations of the rotating shaft 11 in different directions can be effectively damped.

FIG. 4 is a sectional view showing another embodiment of the bearing device of the present invention. The same components as those in the embodiments shown in FIGS. 1 and 2 are designated by the same reference numerals and the description thereof will be omitted. In this embodiment, electrodes 27 and 28 are provided on the inner peripheral side of the bearing housing 13 and the outer peripheral side of the support member 14 at both axial ends of the fluid film damper 16 via electrical insulating materials 25 and 26, respectively. ing. Also in this embodiment, as in FIG. 2, one of the electrodes 27 or 28 is divided and the voltage applied to the electrodes is controlled according to the vibration direction of the rotating shaft to control the viscosity of the fluid in a directional manner. Therefore, it is possible to effectively damp vibrations of the rotating shaft in different directions.

Next, the electrorheological fluid, which is essential to the construction of the present invention, will be described. The Winslow effect of an electrorheological fluid is disclosed in US Pat. No. 2,417,850, in which solid particles (dispersoids) are suspended between two electrodes in an electrically insulating liquid (dispersion medium). Filling with a turbid material, so-called electrorheological fluid, and applying a voltage between both electrodes results in an increase in fluid viscosity due to the effect of an external electric field. Not only can this viscosity be externally controlled by the magnitude of the external electric field, but the excellent effect of extremely good responsiveness can be expected.

Explaining the embodiment of the electrorheological fluid, the electrically insulating liquid as the dispersion medium may be any electrically insulating liquid and is not particularly limited. For example, mineral oil or synthetic oil may be used. Yes, more specifically, naphthenic mineral oil, paraffinic mineral oil, polyalpha-olefin, polyalkylene glycol, silicone, diester, polyol ester, phosphoric acid ester, silicon compound, fluorine compound, polyphenyl ether, alkylbenzene, synthetic hydrocarbon. And so on. The viscosity range of these electrically insulating liquids is 5 to 300 CP at 40 ° C.
Are preferred.

Further, the porous solid particles as the dispersoid are
Commonly used ones are not particularly limited, and examples thereof include silica gel, hydrous resin, diatomaceous earth, alumina, silica-alumina, zeolite, ion exchange resin, and cellulose. These porous solid particles are
Usually, a particle size of 10 nm to 200 μm is 0.1 to 50
Used in a percentage by weight.

Further, in order to enhance the polarization promoting effect, water,
A polarization promoter such as polyhydric alcohol, acid, salt or base is added. In particular, it is preferable to use the porous solid particles, which are dispersoids, in a mode that facilitates dielectric polarization. Examples of the polarization promoting agent include polyhydric alcohols and partial derivatives thereof. As polyhydric alcohol, dihydric alcohol,
Trihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, glycerin,
Examples thereof include propanediol, butanediol, pentanediol, hexanediol and the like. Examples of preferable polyhydric alcohols include triethylene glycol and tetraethylene glycol.

Further, the partial derivative of polyhydric alcohol is a partial derivative of polyhydric alcohol having at least one hydroxyl group, and some of the terminal hydroxyl groups of the above polyhydric alcohol are methyl group, ethyl group and propyl group. , Partial ethers substituted with an alkyl-substituted phenyl group (the number of carbon atoms of the alkyl group substituted with a phenyl group is 1 to 25), etc., and some of the terminal hydroxyl groups are esters with acetic acid, propionic acid, butyric acid, etc. And partial esters thereof.

These polyhydric alcohols or their partial derivatives are usually used in an amount of 1 wt% to 100% based on the porous solid particles.
wt%, particularly preferably 2 wt% to 80 wt% may be used. If the addition amount is less than 1 wt%, the ER effect is small, and if it exceeds 100 wt%, the current easily flows, which is not preferable. The amount of water or polyhydric alcohol used is usually 1 to 100% by weight with respect to the porous solid particles.

Next, the acid, salt and base components will be described. As the acid component, sulfuric acid, hydrochloric acid, nitric acid, perchloric acid, chromic acid, phosphoric acid, inorganic acids such as boric acid, or acetic acid, formic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, oxalic acid, malonic acid, etc. Organic acids are used.

As the salt, a metal or a basic group (N
H ₄ ⁺ , N ₂ H ₅ ^+, etc.) and an acid group, and any of these can be used. Among them, polyhydric alcohols, those which dissolve in a system of polyhydric alcohol partial derivatives and dissociate, for example, those which form typical ionic crystals such as alkali metal and halides of alkaline earth metals,
Alternatively, alkali metal salts of organic acids and the like are preferable. LiCl, NaCl, KCl, MgCl, etc.
₂ , CaCl ₂ , BaCl ₂ , LiBr, NaBr, K
Br, MgBr ₂ , LiI, NaI, KI, AgN
O ₃ , Ca (NO ₃ ) ₂ , NaNO ₂ , NH ₄ NO ₃ , K ₂
SO ₄ , Na ₂ SO ₄ , NaHSO ₄ , (NH ₄ ) ₂ SO ₄
Alternatively, there are metal salts of alkali acids such as formic acid, acetic acid, oxalic acid and succinic acid.

Examples of the base include hydroxides of alkali metals or alkaline earth metals, carbonates of alkali metals, amines, etc., and polyhydric alcohols, polyhydric alcohol partial derivatives, or polyhydric alcohols and / or polyhydric alcohols. Those that dissolve in the system of the alcohol partial derivative and water to dissociate are preferable. As this kind of base, NaOH, KOH, Ca
(OH) ₂ , Na ₂ CO ₃ , NaHCO ₃ , K ₃ PO ₄ , N
a ₃ PO ₄ , aniline, alkylamine, ethanolamine and the like. The above-mentioned salt and base can be used in combination.

The above-mentioned acids, salts and bases are capable of increasing the polarization effect, but when used in combination with a polyhydric alcohol and / or a polyhydric alcohol partial derivative, the polarization effect is further enhanced. The total amount of electrorheological fluid is 0.01 wt% to 5w.
It is preferable to use it at a ratio of t%. If it is less than 0.01 wt%, the ER effect is small, and if it exceeds 5 wt%, it becomes easy to energize and power consumption increases, which is not preferable.
Further, when an acid, salt or base component is added to the electrorheological fluid of this example, it is necessary that the partial esterified product of the polyhydric alcohol is not hydrolyzed.

Further, a dispersant is used to make the dispersed state of the porous solid particles in the dispersion medium uniform and stable. For example, sulfonates, phenates, phosphonates, succinimides, amines, esters, nonionic dispersants and the like are used, and specifically, magnesium sulfonate, calcium sulfonate, calcium phenate, calcium phosphonate, Examples include polyisobutenyl succinimide, sorbitan monooleate and sorbitan sesquioleate. These are usually 0.1
Used at a rate of ~ 15% by weight. However, the dispersant may not be used when the dispersibility of the solid particles is good.

Further, additives such as an antioxidant, an antiwear agent, a corrosion inhibitor, a friction modifier, an extreme pressure agent and an anti-packaging agent may be added.

In the examples of the present invention, an electrorheological fluid comprising alkylbenzene as a dispersion medium, silica gel as a dispersoid, and triethylene glycol as a polarizing agent is used.
Polybutenyl succinimide is added as a dispersant, and 2.6-di-t-butylphenol is added as an antioxidant.

Next, another embodiment of the present invention will be described. In the present embodiment, liquid crystal is used instead of the electrorheological fluid, and when a voltage is applied between the electrodes, the state of the liquid crystal molecules sandwiched between the electrodes, such as the direction and arrangement, is changed to increase or decrease the viscosity of the liquid crystal. The same effect as that of the electrorheological fluid is exhibited. When liquid crystal is used, as shown in FIG. 2, one electrode 20 is replaced with electrodes 20A, 20B, 20
C and 20D do not have to be divided, and the same effect can be obtained even if the electrodes 18 and 20 are integrally formed in a ring shape.

The liquid crystal used in the present invention may be a commercially available product, for example, azo type, azoxy type, benzoic acid phenyl ester type, cyanobiphenyl type, cyanoterphenyl type, cyclohexylcarboxylic acid phenyl ester type,
Phenylcyclohexane system, biphenylcyclohexane system, phenylpyrimidine system, phenyldioxane system, cyclohexylcyclohexane ester system, cyclohexylethane system, cyclohexene system, alkylalkoxytran system, alkenyl system, 2,3-difluorophenylene system, cyclohexylcyclohexane system, bicyclooctane system It is possible to use a liquid crystal of a system, a cubane system, a dicyanohydroquinone system, a cyanothiophenyl ester system, an azomethine system, or the like.

However, the azomethine type is stable,
It is not so preferable because the thickening effect is small. Further, if necessary, additives such as an antioxidant, an antiwear agent, a corrosion inhibitor, and a friction modifier may be added. The above liquid crystals may be used alone or as a mixture. Preferably, various liquid crystal substances are mixed and used in order to improve liquid crystal characteristics. As a concrete example of the liquid crystal, a trade name RDX-4069
A liquid crystal (manufactured by Rodick) was used.

In this embodiment, the following effects are obtained as compared with the above-mentioned embodiment using the electrorheological fluid. Since the applied voltage is small, local damage due to discharge etc. is reduced and the life of the device is extended, the gap between the electrodes can be narrowed and the device can be downsized, and the battery can be used as a power source. Becomes

Since there is no concern about sedimentation of solid particles,
No decrease in thickening effect and clogging of filter. Control is easy because the effect of shear rate is small. Hard to deteriorate.

[0035]

As apparent from the above description, according to the present invention, since the voltage applied between the electrodes can be controlled by the vibration direction of the rotating shaft, the viscosity of the fluid can be controlled in a directional manner. Therefore, it is possible to effectively damp vibrations of the rotating shaft in different directions.

[Brief description of drawings]

1 shows an embodiment of a bearing device of the present invention, FIG. A is a sectional view, and FIG. B is a side view as seen from the left in FIG.

FIG. 2 is a schematic diagram showing an arrangement example of electrodes.

FIG. 3 is a configuration diagram of a control system showing an example of a method of controlling a voltage to an electrode.

FIG. 4 is a sectional view showing another embodiment of the bearing device of the present invention.

[Explanation of symbols]

11 ... Rotating shaft, 12 ... Bearing, 13 ... Bearing housing, 1
4 ... Support member 16 ... Fluid film damper part, 18, 20, 27, 28 ... Electrode, 20A, 20B, 20C, 20D ... Electrode

Claims (3)

[Claims] 1. A bearing for supporting a rotating shaft, a supporting member for supporting the bearing in a bearing housing, a fluid film damper portion formed between the supporting member and the bearing housing, and the supporting member. An electrode provided so as to face the outer peripheral surface and the inner peripheral surface of the bearing housing, and an electrorheological fluid supplied into the fluid film damper portion, one of the electrodes is divided and applied between the electrodes. Bearing device capable of controlling the generated voltage by the vibration direction of the rotating shaft. 2. A bearing for supporting a rotating shaft, a supporting member for supporting the bearing in a bearing housing, a fluid film damper portion formed between the supporting member and the bearing housing, and the supporting member. An electrode provided opposite to the outer peripheral surface and the inner peripheral surface of the bearing housing, and a liquid crystal supplied to the fluid film damper portion are provided, and the voltage applied between the electrodes can be controlled by the vibration direction of the rotating shaft. A bearing device characterized by: 3. The bearing device according to claim 2, wherein one of the electrodes is divided.