Source: http://www.google.com/patents/US6283637?dq=U.S.+Patent+No.+4,528,643
Timestamp: 2015-07-04 15:04:12
Document Index: 247476112

Matched Legal Cases: ['art. 7', 'art 2', 'art 2', 'art 2', 'art 2', 'art 2', 'art 2', 'art 2', 'art 2']

Patent US6283637 - Method for detuning the natural frequency of a rotatable part as well as a ... - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsA method and apparatus for detuning the natural frequency of a rotatable part, which is rotatably disposed in the shaft bearing, and in the case of which the axis of rotation of the rotatable part is arranged axially identically with the axis of rotation of the shaft bearing, as well as to a correspondingly...http://www.google.com/patents/US6283637?utm_source=gb-gplus-sharePatent US6283637 - Method for detuning the natural frequency of a rotatable part as well as a tunable rotatable partAdvanced Patent SearchPublication numberUS6283637 B1Publication typeGrantApplication numberUS 09/329,800Publication dateSep 4, 2001Filing dateJun 10, 1999Priority dateJun 13, 1998Fee statusLapsedAlso published asDE19826176A1, DE19826176C2, EP0964174A2, EP0964174A3Publication number09329800, 329800, US 6283637 B1, US 6283637B1, US-B1-6283637, US6283637 B1, US6283637B1InventorsJuergen Schnur, Silvia TomaschkoOriginal AssigneeDaimlerchrysler AgExport CitationBiBTeX, EndNote, RefManPatent Citations (19), Referenced by (4), Classifications (7), Legal Events (4) External Links: USPTO, USPTO Assignment, EspacenetMethod for detuning the natural frequency of a rotatable part as well as a tunable rotatable part
US 6283637 B1Abstract
A method and apparatus for detuning the natural frequency of a rotatable part, which is rotatably disposed in the shaft bearing, and in the case of which the axis of rotation of the rotatable part is arranged axially identically with the axis of rotation of the shaft bearing, as well as to a correspondingly tunable rotatable part. For compensating an axial play and/or a disturbing sound effect, the clamping conditions are changed by a reversible change of the axial course and/or of the axial contact pressure of an axial adjusting unit onto the rotatable part, the axial adjusting unit being manufactured of a piezoelectrically active material.
What is claimed is: 1. A method for detuning the natural frequency of a rotatable part disposed in a shaft bearing wherein the axis of rotation of the rotatable part is coaxial with an axis of rotation of a shaft bearing, said method comprising the steps of: detecting the vibrations which occur at the rotatable part;
providing a radial adjusting unit made of a piezoelectrically active material; providing a change in the clamping condition by a reversible change in one of a radial extension and a pressure against said rotating part, wherein said change in clamping condition are controlled as a function of said detected vibrations of said rotatable part; and converting the control change in clamping condition to a change in transmission function of the detected vibration existing between said rotatable part and the shaft bearing or between the rotating part and a component contacting the shaft bearing. 2. Method according to claim 1,
wherein, in the case of a rotatable part of an internal-combustion machine, particularly of an internal-combustion engine, particularly of an internal-combustion, the clamping conditions are changed as a function of a parameter, particularly of the rotational speed and/or the crank angle of an internal-combustion engine. 3. Method according to claim 1,
wherein the clamping conditions are changed as a function of at least one of the temperature of the rotatable part and of the shaft bearing. 4. Method according to claim 1,
wherein data for controlling the clamping conditions are retrieved from a set of data filed in a preferably electronic data memory. 5. Method according to claim 1,
wherein a natural frequency of the rotatable part is changed by changing the clamping conditions. 6. Apparatus for detuning the natural frequency of a rotatable part disposed rotatably in a shaft bearing and having an axis of rotation which is coaxial with an axis of rotation or an axis of symmetry of the shaft bearing, said apparatus comprising:
an axial adjusting unit made of a piezoelectrically active material wherein at least one of the effective radial dimension of said axial adjusting unit and an axial contact pressure onto the rotatable part in the area of the rotatable part is changeable in a reversible manner during rotation of said rotatable part. 7. The apparatus according to claim 6,
wherein the rotatable part is a rotating system element, preferably a crankshaft or a camshaft of an internal-combustion engine, particularly of a diesel or gasoline engine. 8. The apparatus according to claim 6,
wherein the rotatable part is a rotating system element, preferably a shaft or a rotator of an electric motor. 9. The apparatus according to claim 6,
wherein the rotatable part is a rotating system element of a propeller or a jet engine. Description
The invention relates to a method for detuning the natural frequency of a rotatable part which is rotatably disposed in the shaft bearing, and in the case of which the axis of rotation of the rotatable part is arranged axially identically with the axis of rotation of the shaft bearing, as well as to a tunable rotatable part which is rotatably disposed in the shaft bearing, and in the case of which the axis of rotation of the rotatable part is arranged axially identically with the axis of rotation the shaft bearing.
Furthermore, machines having rotating parts have at least usually a certain disturbing sound effect. One reason for these disturbing noises is, among others, that the rotating rotatable parts, particularly shafts, introduce vibrations into other components. Resonance frequencies are important for the transmission of vibrations between components and for the introduction of vibrations from one component to another. The mathematical relationship of this frequency-dependent transmission is called transmission function.
From U.S. Patent Document U.S. Pat. No. 5,332,061 A1, a method is known for suppressing vibrations introduced into the vehicle body as well as a corresponding vehicle. The concerned introduced vibrations originate from the engine and, in this case, particularly from the moving parts, such as the rotating crankshaft or camshaft. The vibrations are transmitted at the connection points of the engine with the vehicle body. For damping these vibrations, the vehicle has shakers, thus, mechanical vibration exciting devices which are arranged in the area of at least some connection points of the engine with the vehicle body. During the operation of the engine, the shakers are excited as a function of the rotational speed of the engine at the resonance frequencies in antiphase to the vibrations coming from the engine, whereby the transmission of the introduced vibrations is at least dampened. In this case, the corresponding frequencies and their amplitudes for the artificial secondary vibrations introduced in a targeted manner are taken from a previously filed data field.
A further development of the above system for influencing the subjectively perceived driving sensation is known from German Patent Document DE 195 31 402 A1. According to this document, as a function of a parameter and in this case particularly of the rotational engine speed and/or the vehicle speed, not only the airborne sound but also the structure-borne sound or vibrations perceived by the body are influenced. For this purpose, depending on the size of the parameter, certain data are read out of a data field and, by means of vibration exciting devices are converted to artificial vibrations which, among others, can also be perceived by the body. As a result of these measures, in conjunction with the influencing of the acoustically perceived airborne sound, positive as well as negative interferences of the targeted introduced artificial secondary vibrations can be generated with the primary vibrations which occur on the vehicle side when the vehicle is operated. As desired, the interferences can reduce the perceived impression or simulate a certain impression, for example, a shifting in the case of a vehicle provided with an infinitely variable speed transmission.
It is an object of the invention to develop a method by means of which the perceivable vibrations of an engine having rotating rotatable parts and, at the same time, a possibly occurring axial play can be at least reduced. Furthermore, it is an object of the invention to suggest a new system by means of which perceivable vibrations and, at the same time, a possibly occurring axial play can be at least reduced.
According to the invention, as the result of the targeted and reversible change of the axial adjusting unit having particularly piezoelements or of the contact pressure axially acting upon the rotatable part, the axial clamping conditions during the operation can be changed by a targeted intervention from the outside. The changing of the clamping conditions has, for example, the result that the values of the inherent vibrations of the rotatable part and also the transmission function from the rotatable part to another component are changed. As the result of the change of the transmission function, the transmission of vibrations, thus of the transmittable energy, coming from the rotatable part, into another component are changed, particularly at least reduced.
In the case of the axial adjusting unit, the intervention takes place by the application of an electric voltage. This measure leads to a change of the resonance or natural frequencies of the rotatable part and also to a change during the transmission and introduction of vibrations. The respective resonance frequencies are important for the transmission of vibrations between components and for the introduction of vibrations from one component to another component, The mathematical relationship of this frequency-dependent energy transmission or vibration transmission is called transmission function.
As the result of this intervention, the resonance between the rotatable part and the environment transmitting the vibrations is therefore disturbed, whereby the sound effects which are particularly perceived to be disturbing are reduced. Since, in the case of an existing axial play, the change of the axial clamping conditions is connected by an axial movement at least of a part of the axial adjusting unit, simultaneously at least a reduction of this axial play can be achieved.
Meaningful further developments of the invention are contained in the subclaims. In addition, the invention is explained in detail by means of embodiments illustrated in the drawings.
FIG. 1 is a view of a face-side receiving arrangement of a rotatable part with an axial adjusting unit arranged on the interior side in a surrounding component;
FIG. 2 is a view of another face-side receiving arrangement of a rotatable part;
FIG. 3 is a view of an axial adjusting unit which is constructed in the manner of a seal with integrated piezoelements;
FIG. 4 is a view of an axial adjusting unit which is constructed in the manner of a seal with integrated and oriented piezoelements; and
FIG. 5 is a view of an axial adjusting unit and an enlargement of its cutout, the axial adjusting unit being constructed in the manner of a seal with integrated and oriented piezoelements as well as with integrated contacts.
FIG. 1 illustrates a face-side receiving arrangement of a rotatable part 2 in a surrounding component 7. The rotatable part 2 has a stop on which the radius changes abruptly. The stop of the rotatable part rests directly on the interior ring 5 of the shaft bearing and is therefore arranged in the axial direction without play in the shaft bearing. The shaft bearing has an outer shell 4, and inner shell 5, as well as balls 6 rollably arranged between the outer shell 4 and the inner shell 5.
The inner shell 5 and the outer shell 4 each have only one contact surface or sliding surface for the balls 6 which is situated transversely with respect to their axis of rotation. As the result of the construction, the inner shell 5 can be axially displaced to a certain extent relative to the outer shell 4.
In the case of an existing axial play, the whole arrangement is pushed in the above-described case by way of the countering in the direction of the stop of the rotatable part 2 and the axial play is at least reduced. As the result of the change of the geometry of the piezoelements of the axial adjusting unit 31, a possibly occurring axial play can therefore also be compensated.
The secondary vibration is expediently changed as a function of the occurring vibration. For this purpose, it is useful to sense the occurring vibration, to analyze it by means of a mathematical algorithm—such as a Fourier transformation—and, as a result, by means of correspondingly generated sets of data, excite the half-shell piezoelements of the axial adjusting unit 31 to carry out a corresponding secondary vibration.
FIG. 2 shows another embodiment of a face-side receiving arrangement of a rotatable part 2 in a surrounding component 7. The shaft bearing present here corresponds with respect to the construction to that of FIG. 1. The rotatable part 2 has a stop at which the radius changes abruptly. The stop of the rotatable part rests directly on the inner ring 5 of the shaft bearing and, as a result, is arranged in the axial direction without play in the shaft bearing.
In the case of an existing axial play, the whole arrangement is pushed in the above-described case by way of the dome in the direction of the stop of the rotatable part and the axial play is at least reduced. As the result of the change of the geometry of the piezoelements of the axial adjusting unit 31, a possibly occurring axial play can therefore also be compensated.
Furthermore, the piezoelements of the axial adjusting unit 31, in the event of a vibration occurring in the rotatable part 2, can be excited by the application of an alternating voltage to carry out a secondary vibration. The secondary vibration is transmitted to the rotatable part 2 by way of the components conducting the power flux and is caused to enter an interference with the occurring vibration, particularly a natural vibration of the rotatable part 2. By means of the interference with the secondary vibration, the vibration occurring at the rotatable part is changed and particularly damped.
In a useful manner, the radial adjustment of the axial adjusting unit 31 and the artificial generating of the secondary vibration can be connected with one another, whereby the arrangement or the method according to the invention becomes more flexible.
The offset voltage controls the radial course or the radial contact pressure of the half-shell piezoelements of the axial adjusting unit 31, while the alternating voltage excites the piezoelements of the axial adjusting unit 31 to carry out a secondary vibration. As a result, the half-shell piezoelements of the axial adjusting unit carry out a secondary vibration whose zero point is arranged at the site which is determined by the offset voltage.
Instead of the axial adjusting units 31 illustrated in FIGS. 1 to 2, which are always formed of massive piezoelements, an axial adjusting unit 31 can, in a special manner, also be constructed as a seal, in which the piezoelements 14, 14′, 14″ are arranged in a plastic matrix 6. Corresponding embodiments of these (active) seals are illustrated in FIGS. 3 to 5. In the case of these seals, it is advantageous that such axial adjusting units (31), in addition to the sealing effect, also exercise a protective effect on the piezoelements 14, 14′, 14″ which is the result of the plastic matrix 16 of the seal surrounding them.
FIG. 3 shows a seal of an axial adjusting unit 31 with a matrix 16 consisting of a preferably electrically conductive plastic material in which several piezoelements 14 of any size, orientation and physical design are embedded. Such an arrangement is generally called a 0-3-piezoceramics-polymer-composite. In the area of the wall of the seal, electric contacts 15 are advantageously provided which are connected by electric control lines 20 with a control unit (not shown).
FIG. 4 illustrates another active seal of an axial adjusting unit 31 with a plastic matrix 16 in which several piezoelements 14′ are embedded. In contrast to the embodiment according to FIG. 3, these piezoelements 14′ are of a defined size and shape and, in addition, are arranged in an oriented manner. Such an arrangement is generally called a 1-3-piezoceramics-polymer composite.
In the area of the wall of the seal, electric contacts 15 are also arranged which are also connected by electric control lines 20 with a control unit (not shown). In contrast to the seal according to FIG. 3, in the case of the seal according to FIG. 4, each piezoelement 14′ is electrically contacted individually and can therefore also be individually triggered in a separate manner.
The piezoelements 14′ of the seal of an axial adjusting unit 31 are preferably constructed in the manner of piezostacks and/or are arranged in a lamella-type manner and particularly aligned behind one another in the seal.
During the manufacturing of the seal, the thus arranged piezoelements 14′ are expediently electrically contacted before they are embedded in the plastic material forming the matrix 16 of the seal. So that the seal of an axial adjusting unit 31 continues to fulfill its normal purpose, the plastic material forming the matrix 16 is preferably manufactured of a polymer and particularly of an elastomer.
FIG. 5 illustrates an active seal of an axial adjusting unit 31 with a plastic matrix 16 in which several piezoelements 14″ are embedded with assigned piezoelectric sensors 17. With respect to the construction and the oriented arrangement, the piezoelements 14″ are largely similar to those according to FIG. 4.
Advantageously, in the case of such a seal of an axial adjusting unit 31, by means of the sensor 17, a residual vibration remaining after a desired excitation of the piezoelements 14″ can be determined and correspondingly controlled. Together with the pertaining electronic system, this piezo/sensor element 4″ therefore forms a control circuit. For this reason, it is, among other things, advantageous to arrange the sensor 17 in the power flux direction and/or in parallel to the deflection direction of the amplitude to be expected or of the modes of the transmitted vibration behind the excitable piezoelement 14″.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS4850719Sep 12, 1988Jul 25, 1989The Torrington CompanyBearing with adjustable stiffnessUS5221146Apr 13, 1992Jun 22, 1993Nissan Motor Co., Ltd.Structure of bearing of geared shaftUS5332061Mar 12, 1993Jul 26, 1994General Motors CorporationActive vibration control system for attenuating engine generated vibrations in a vehicleUS5434783Jan 3, 1994Jul 18, 1995Nissan Motor Co., Ltd.Active control systemUS5509198 *Jun 6, 1994Apr 23, 1996Nsk Ltd.Preloading method for preload-adjustable rolling bearing and manufacture of the sameUS5564840Jan 2, 1996Oct 15, 1996The Torrington CompanyPreload adjustment apparatus and methodUS5660481 *Nov 24, 1993Aug 26, 1997Ide; Russell D.Hydrodynamic bearings having beam mounted bearing pads and sealed bearing assemblies including the sameDE3123590A1Jun 13, 1981Jan 5, 1983Lemfoerder Metallwaren Ag"kugelgelenk"DE3606042A1Feb 25, 1986Sep 25, 1986Torrington CoLageranordnungDE3900121A1Jan 4, 1989Jul 19, 1990Inst Produktionstechnik KarlsrBall bearing axial tension regulating assemblyDE4227366A1Aug 19, 1992Feb 24, 1994Schaeffler Waelzlager KgBearing with dampened vibrations esp. for machine tool - has two bearing elements rotatable relative to each other across at least one radial bearing and in at least one axial direction are located fixed to each other by axial bearingDE9301334U1Feb 1, 1993Apr 1, 1993Ing. Lang & Menke Gmbh, 5870 Hemer, DeTitle not availableDE19531402A1Aug 26, 1995Feb 27, 1997Fichtel & Sachs AgVorrichtung und Verfahren zum Beeinflussen von Schwingungen in einem Fahrgastraum eines Kraftfahrzeugs und Vorrichtung und Verfahren zum Erkennen von Defekten an einem KraftfahrzeugDE19541245A1Nov 6, 1995May 7, 1997Klein Schanzlin & Becker AgGleitlagerung f�r eine MaschinenwelleDE69508203T2Dec 12, 1995Jul 8, 1999Koyo Seiko CoW�lzlager mit hydraulischer VorspannungsvorrichtungEP0377145A2Dec 13, 1989Jul 11, 1990Institut F�r Produktionstechnik Karlsruhe GmbhAxial pretension-adjusting device for roller bearings and spindle nutsGB2279999A Title not availableJPH01266320A Title not availableJPS61127922A Title not available* Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS6508592 *Nov 7, 2000Jan 21, 2003Umbra Cuscinetti SpaDevice for measuring and adjusting preloading on bearingsUS6520678 *Mar 27, 2001Feb 18, 2003Spicer Driveshaft, Inc.Vehicle center bearing assembly including piezo-based device for vibration dampingUS6672434 *Mar 7, 2002Jan 6, 2004Daimlerchrysler AgMethod and device for influencing the transfer of vibrations of a vibration generator to an object connected to it, in particular of engine vibrations to the body of a motor vehicleUS7217038 *Mar 18, 2005May 15, 2007Ntn CorporationFixing structure for rolling bearing* Cited by examinerClassifications U.S. Classification384/519, 384/1International ClassificationF16C25/06Cooperative ClassificationF16C25/06, F16C27/04European ClassificationF16C27/04, F16C25/06Legal EventsDateCodeEventDescriptionSep 2, 1999ASAssignmentOwner name: DAIMLERCHRYSLER AG, GERMANYFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SCHNUR, JUERGEN;TOMASCHKO, SILVIA;REEL/FRAME:010207/0655;SIGNING DATES FROM 19990715 TO 19990720Mar 23, 2005REMIMaintenance fee reminder mailedSep 6, 2005LAPSLapse for failure to pay maintenance feesNov 1, 2005FPExpired due to failure to pay maintenance feeEffective date: 20050904RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services