WO2006089639A1

WO2006089639A1 - Method and device for damping vibration

Info

Publication number: WO2006089639A1
Application number: PCT/EP2006/001117
Authority: WO
Inventors: Dr. Arbogast Grunau
Original assignee: Schaeffler Kg
Priority date: 2005-02-22
Filing date: 2006-02-08
Publication date: 2006-08-31
Also published as: DE102005007985A1

Abstract

The invention relates to a method and a device for damping the vibration of machines or other components (1) which are excited in such a way as to vibrate, or are self-vibrating, by means of piezoelectric element structures (5a, 5b ... 5n; 5a', 5b'... 5n') acting thereon. The aim of the invention is to avoid an external energy supply and to enable a reliable operation with a maximum amount of vibration damping. To this end, at least one first piezoelectric element structure (5a; 5n', 5b') extracts energy from transmitted or generated vibration by being deformed and excited in such a way that electrical energy is generated, and the generated electrical energy is supplied to at least one other piezoelectric element structure (5b; 5a) which extends, as a result, away from the vibration direction, whereby a defined counter-impulse or a defined counter-force is generated, reducing the original vibration amplitude.

Description

Name of the invention

Method and device for vibration damping

Field of the invention

The invention relates to a method and a device for vibration damping of vibrating excited or self-oscillating machine or other components by means of acting on the same piezo element structures.

Background of the invention

Methods and devices of the generic type have been known for some time.

Thus, from DE 40 07 443 A1 a so-called active vibration control is known which comprises a vibration suspension, with which a body is fastened via an intermediate body and constructive actuating elements on a support. The structural actuators can change their dimensions in a controllable manner by the action of signals. These are supplied by a computer which contains information from arranged on the intermediate body sensors. The vibration suspension provides the intermediate body with reducing compensating forces controlled by its vibration. As a constructive actuators electrodynamic, piezoelectric, hydraulic and magnetostrictive actuators are proposed, which are intended to increase or decrease their dimensions in accordance with a control signal.

Other, above basic idea developing solutions are the documents US 5,221, 146 A, US 6,394,655 B1, DE 198 26 172 A1, DE 198 26 174 A1 and DE 198 26 177 A1 are known and are concerned essentially with piezoelectric actuators.

Thereafter, it is proposed by US Pat. No. 5,221,146 A to actively influence rotary bearings by means of one or more actuated piezoelectric actuators and corresponding piezoelectric sensors so that any vibrations are eliminated. In this case, essentially by means of the piezoelectric actuators, a phase-shifted by 180 ° to the natural oscillation of a wave oscillation is generated, which is the said natural vibration of the shaft superimposed and thus extinguished.

Comparable is proposed in US 6,394,655 B1, DE 198 26 172 A1 and DE 198 26 174 A1. Furthermore, it is proposed in these documents to achieve vibration damping by radially extending semi-angular piezoelectric elements of a so-called radial adjustment of the bearing by applying a direct electrical voltage, as a result of which the contact pressure against the shaft and thus the previously existing clamping conditions and thus also the Resonance or natural frequencies of the rotating part or the shaft change.

With the DE 198 26 174 A1 is also proposed to equip a so-called Axialverstelleinheit the camp with the subject piezoelectric elements. Finally, it is proposed in this document to tap electrical energy (electrical voltage) of piezoelectric elements z. B. can arise as a result of the fact that vibrations transmitted from a rotating part exert pressure on the piezo elements and deform them. This electrical energy can then be converted to heat, depriving the system of vibratory energy.

Although the basic idea described above is also pursued with DE 198 26 177 A1, this document is not only concerned with Rotativlagern, but includes other applications in the closer consideration in order to make a targeted influence of perceptible vibrations that emanate from an at least indirectly motor-driven vehicle, in particular from a perceptible in the passenger compartment noise. In the region of a transition of two, at least indirectly and at least partially contacting, in particular overlapping components at least one in its geometry controllable variable and excitable to vibrations spacer, in particular a piezo element, arranged. About the contact area of the two components, which may be not only rotating components, but also solid or surface components are transmitted between the same vibrations. In this case, the piezoelectric element is to be excited to a secondary oscillation which is interfered with the transmitted oscillation, whereby the total energy and / or the composition of the frequencies of the transmitted oscillations is changed.

Apart from the suggestion to extract vibration energy from the system by tapping electrical energy (electric voltage) from piezo elements and converting it into heat, the above proposals for vibration damping have in common that they have an external control with measuring means and external energy supply associated with a relatively high material, cost and maintenance. This is where the invention described below begins.

Object of the invention

The invention is accordingly an object of the invention to provide a simple and inexpensive method for vibration damping of vibrating or self-oscillating machine or other components by means of acting on the same piezoelectric element structures, which in particular avoids an external power supply. The invention also relates to a Device for carrying out this method, which in particular enables safe operation with the greatest possible vibration damping and further requires a relatively small amount of energy.

Summary of the invention

The invention is based on the finding that the self-generated electrical energy of the piezoelectric element structures can advantageously be used to control further piezoelectric feedback structures in order to effectively damp vibrations of machine components or other components.

The object is achieved according to claim 1 first by a method for vibration damping of vibrating or self-oscillating machine or other components by means of acting on the same piezoelectric element structures, wherein at least a first piezo element structure of the transmitted mechanical vibration energy withdraws energy by the same deformed and is accordingly stimulated to generate electrical energy. This generated electrical energy is then supplied to at least one further piezoelectric element structure which, as a result, expands against the direction of oscillation, as a result of which a defined counter-pulse or a defined counter-force is generated which reduces the original oscillation amplitude.

By this measure, external electrical energy for operating the at least one further piezoelectric element structure is dispensable in a particularly advantageous manner, which is accompanied, inter alia, by a reduced wiring complexity.

The subclaims describe preferred developments or refinements of the method according to the main claim. Thereafter, it is provided in an advantageous embodiment of the invention that is generated delayed in response to a desired damping characteristic of the counter-pulse. The extent of the time delay of the counter-pulse can be regulated or adjusted electronically.

Likewise, it may also be appropriate for the degree of the time delay of the counterpulse to be regulated or set by a defined physical configuration of the at least one further piezoelectric element structure.

Furthermore, it is also possible for the degree of deceleration of the counter-pulse and / or the force effect thereof to be regulated or adjusted by the conversion of defined energy portions of the electrical energy generated by the at least one first piezoelectric element structure into heat energy.

In a further embodiment of the invention, it is provided that the degree of delay of the counter-pulse is adjusted so that the generated Gegenim- pulse shortly before reaching the vibration maximum of the machine component or other component is effective.

As the invention still provides, the degree of the counter-pulse or the counterforce and / or the extent of the time delay of the counter-pulse can be determined empirically and / or calculated, for example, during operation.

The device for vibration damping of vibrated to vibrate

Machine components or other components by means of attached to the same piezoelectric element structures is characterized in that two or more piezoelectric element structures such arranged to each other and electrically connected, that of at least one piezoelectric element structure by deformation of the same generated electrical energy of at least one further Piezoelementstruktur zuleitbar, which in turn is adapted to expand by said energy supply against the direction of vibration and to reduce the original amplitude of vibration a defined counter-pulse or a defined counterforce produce.

The scope of the invention further includes that the piezoelectric element structures are each formed by one or more discrete piezoelectric elements in the form of quartz elements and / or by one or more quartz films as a thick layer.

The electrically interconnected piezoelectric element structures can furthermore be arranged side by side as well as stacked in the direction of oscillation.

Further, the piezoelectric element electrically connected structures can ^~ immediately adjacent or spaced from one another to be disposed.

It is further proposed that the electrically interconnected piezoelectric element structures are connected via at least one electronic component which is suitable for delaying the counter-pulse in time.

Such an electronic component can be formed, for example, by at least one diode or a suitable other, the time sequence of the counter-pulse influencing electronic component.

According to another advantageous measure for the time delay of

Counterimpulse, it is provided that the piezoelectric element structure which expands counter to the direction of oscillation by said energy supply has a certain physical design which influences the time-dependent lent sequence of the said counterpulse allowed.

It has proved to be advantageous to dimension the piezoelectric element structure which expands in the direction of elongation by the aforementioned energy supply against the direction of oscillation to be shorter than the piezoelectric element structure which generates electrical energy by deformation.

Finally, according to a third possible measure for the time delay of the counter-pulse, it is provided that the piezoelectric element structure producing electrical energy due to deformation is assigned at least one electronic component for converting electrical energy into thermal energy.

Furthermore, it is proposed in the sense of the invention that the at least one electronic component for converting electrical energy into thermal energy is formed by an electronic component that generates an electrical resistance or an inductance.

The extent of the delay of the counter-pulse is preferably set or selected such that the generated counter-pulse is effective shortly before reaching the maximum vibration of the machine or other component.

The method according to the invention and the device according to the invention can be used both for vibration damping of bearing components on rotary or linear bearings and for vibration damping of solid components, such as oil sump, engine block, engine mount and the like and / or surface components, such as panels, shuttering panels, trim parts, body parts, window panes, etc . be used on machinery and equipment, in particular on vehicles and / or aircraft of all kinds use. Brief description of the drawings

The invention will be described below with reference to the accompanying drawings

Embodiments explained in more detail. It shows

1 is a sectional view of an inventively designed Rotativla- gers,

2 shows the section l-l of FIG. 1,

FIG. 3 shows the detail "Z" according to FIG. 1 according to a first possible embodiment, and FIG

Fig. 4 shows the detail "Z" of Fig. 1 according to another possible embodiment.

Detailed description of the drawings

Fig. 1 shows very schematically the radial section of a machine part 1 in the form of a Rotativlagers, which in the present case comprises a shaft 2, which is rotatably mounted within a bearing housing 4 by means of a rolling bearing 3 or a sliding bearing.

Due to wear, dimensional deviations, changing loads and other causes, the shaft 2 can generate vibrations and / or oscillations are transmitted to this shaft 2 by a drive, not shown in detail, for example an internal combustion engine, which in turn can be accompanied by disadvantageous noise developments ,

Especially in vehicle construction, it is endeavored to significantly dampen such vibrations and accordingly to keep the noise level as low as possible.

In order to dampen such vibrations, it is known per se, Piezoelement- structures, which in turn are arranged on the vibrating machine component or other component 1 and can act on this, by applying an alternating voltage to excite a secondary vibration.

This secondary oscillation can, as already described in the introduction, be interfered with the natural oscillation of a rotary part, in the present case of the shaft 2, whereby the oscillations occurring are changed, preferably damped. Conventionally, this AC voltage or the required e- lectric energy is provided by an external power supply.

As can also be seen from FIGS. 1 and 2, a plurality of piezoelement structures 5a, 5b... 5n arranged uniformly over the circumference of the shaft 2 are provided between the roller bearing 3 and the bearing housing 4.

These piezoelectric element structures 5a, 5b... 5n each consist of a discrete piezo element in the form of quartz elements, which in turn are arranged side by side and at a distance from one another and form a segmented quartz ring, so to speak, whereby the system is independent of the force direction.

The piezoelectric element structures 5a, 5b... 5n or discrete piezoelectric elements are known to each have a conductive layer 6, which in turn is electrically decoupled from surrounding components, in the present case the roller bearing 3 and the bearing housing 4, by an insulating layer 7 (FIGS. 3 and 4).

If the shaft 2 is loaded radially with an oscillating force F and is supported by the rolling bearing 3 and the piezoelectric element structures 5a, 5b... 5n or the discrete piezo elements on the bearing housing 4, then in the piezo element structures 5a, 5b. 5n generates electrical energy or a charge, which in turn is proportional to the applied force F with a fairly good approximation. On the one hand, this electrical energy / charge can conventionally be converted into heat by way of resistors or other electronic components, whereby vibration energy can be withdrawn from the system (not shown in detail).

In contrast, it is proposed according to the invention to use this self-generated electrical energy / charge for triggering or directly for controlling the active vibration damping, whereby external sources of electrical energy are dispensable.

Fig. 3 shows a first preferred embodiment of a suitable device for vibration damping. There, two piezoelectric element structures 5a, 5b arranged side by side in the direction of oscillation are shown in the form of discrete piezoelectric elements, which in turn are electrically connected to one another.

According to the invention, the electrical energy generated by the one piezoelectric element structure 5a as a result of deformation is supplied to the second piezoelectric element structure 5b, whereby it expands counter to the current oscillation direction and generates a defined counter-pulse or a defined counter-force which reduces the original oscillation amplitude.

Instead of forming individual piezoelement structures 5a, 5b... 5n by individual discrete piezo elements, it may also be appropriate to combine two or more piezo elements into a piezoelement structure 5a, 5b... 5n which is uniform in terms of the task assignment, which in turn then may be combined can also be electrically connected to each other (see also Fig. 4). Such a piezoelectric element structure 5a, 5b... 5n can then come into operative connection with another piezoelectric element structure 5a, 5b... 5n by virtue of the piezoelectric element structure 5a, 5b... 5n consisting of a plurality of individual piezoelectric elements electrical energy for actuating or controlling the other, for example, also from a plurality of piezoelectric elements or a piezoelectric element existing piezoelectric element 5a, 5b ... 5n provides.

Instead of individual piezo elements or quartz elements, however, quartz films may also be used as thick layers, preferably segmented thick layers (not shown in greater detail).

It is also conceivable, in adaptation to certain other applications, as exemplified below, the mutually corresponding Piezoelementstrukturen 5a, 5b ... 5n seen in the direction of vibration not adjacent to each other, but stacked or layered to arrange and / or to a spacing between the piezoelectric element structures 5a, 5b ... 5n to be omitted, in which case any required segmentation by a further insulating layer is accomplished (not shown in detail).

In addition, it has proven to be advantageous, depending on a desired damping characteristic to generate the counter-pulse delayed in time.

The extent of the time delay is preferably electronically controlled or adjusted, wherein, according to FIG. 3, the two piezo element structures 5a, 5b or the discrete piezo elements have a suitable electronic element 8, in this case a diode, which is known per se and influences the time sequence of the counterpulse , are electrically connected to each other. Furthermore, it has proven to be expedient to set or select the delay of the counter-pulse so that it becomes active shortly before the oscillation maximum is reached. However, other settings of the delay are conceivable to generate a certain counter-pulse, the extent of which can be empirically determined by experiments or calculated in advance. It is also possible to have this calculation performed online by a microcomputer integrated in the bearing 3.

Furthermore, it has been found that the extent of the time delay of the counter-pulse can also be regulated or adjusted by means of a defined design of a piezoelectric element structure 5a ^' or of a piezoelectric element which is supplied with electrical energy or a charge.

Fig. 4 shows a correspondingly formed device, wherein between two piezoelectric element structures 5n ^' and 5b ^', the piezoelectric element structure 5a ^'is arranged, which in turn is dimensioned in the extension direction by an amount S shorter than the other two piezoelectric element structures 5n ^' , 5b '.

The two piezoelectric element structures 5n ^' , 5b ^' release electrical energy or charge when the force changes due to deformation; they are compressed in the direction of force. The generated electrical energy or charge is the piezoelectric element structure 5a ^' fed, which extends in the sequence. The two piezoelement structures 5n ^' , 5b ^' can thus, as already indicated above, be regarded as a functional unit.

At a time ti, the two piezo element structures 5n ', 5b' are so shortened and the piezo element structure 5a ^' extended so that the original game (S) is balanced. By this measure, the rigidity of the arrangement changes in an advantageous manner, which with a corresponding design of the components with a more or less strong impulse against the Wälzla ger 3 and against the current direction of vibration is accompanied.

As further shown in FIG. 3, the electrical connection between the two piezoelement structures 5a, 5b is assigned an electronic component 9 for the conversion of electrical energy into thermal energy. This electronic component 9 can be formed, for example, by an electronic component that generates an electrical resistance or an inductance.

Although it is known per se with such a component 9 to escape from the system vibration energy, but this arrangement is now intended to convert only defined energy components in heat, thereby also regulating or setting the delay of the counter-pulse and / or a Influencing the power of the same is possible.

With the knowledge of the invention, it is self-evident for the person skilled in the art that the measures for vibration damping described separately above can be used in any combination, which are thus included by the invention.

The embodiments described in more detail below focus on a vibration damping of a rotary bearing. However, the invention is not limited to these embodiments. Further applications are in particular also on linear bearings, solid components, such as oil pan, engine block, engine mount and the like and / or surface components, such as Panele neele, shuttering panels, trim parts, body panels, windows and the like on machinery and equipment, especially on driving and / or aircraft of any kind, which are disadvantageously excited to vibrate or even produce vibrations. reference numeral

1 machine part 2 shaft

3 rolling bearings

4 bearing housing

5a-5n piezo element structures

5a'-5n ^' piezoelectric element structures 6 conductive layer

7 insulating layer

8 electronic component

9 electronic component

Claims

claims

1. A method for vibration damping of vibrating or self-oscillating machine or other components (1) by means of acting on the same piezoelectric element structures (5a, 5b ... 5n;

5a ^' , 5b ^' ... 5n ^' ), characterized in that at least one first piezoelectric element structure (5a; 5n', 5b ^' ) extracts energy from a transmitted or generated vibration by deforming it and accordingly exciting it to generate electrical energy, and the generated electrical energy is fed to at least one further piezoelectric element structure (5b; 5a), which consequently expands counter to the direction of oscillation, whereby a defined counter-pulse or a defined counter-force is generated, which reduces the original oscillation amplitude.

2. The method according to claim 1, characterized in that in response to a desired damping characteristic of the Gegenim- pulse is generated delayed in time.

3. The method according to claim 2, characterized in that the extent of the time delay of the counter-pulse is electronically controlled or adjusted.

4. The method according to any one of claims 2 or 3, characterized marked, that the extent of the time delay of the counter-pulse by a defined physical design of the at least one further piezoelectric element structure (5a ^' ) is regulated or adjusted.

5. The method according to any one of claims 2 to 4, characterized in that the degree of delay of the counter-pulse and / or the Force effect of the same by the conversion of defined energy components of the at least one first piezoelectric element structure (5a) generated electrical energy into heat energy is regulated or adjusted.

6. The method according to any one of claims 2 to 5, characterized in that the degree of delay of the counter-pulse is set so that the generated counter-pulse shortly before reaching the maximum vibration of the machine or other component (1) is effective.

7. The method according to any one of claims 1 to 6, characterized in that the measure of the counter-pulse or the counter-force and / or the extent of the time delay of the counter-pulse is determined empirically and / or calculated.

8. A device for vibration damping of vibrating excited machine or other components (1) by means acting on the same piezoelectric element structures (5a, 5b ... 5n; 5a ^' , 5b' ... 5n ^' ), characterized in that two or more Piezoelement structures (5a, 5b

... 5n; 5a ', 5b' ... 5n ') are arranged relative to each other and electrically connected to one another such that the electrical energy generated by at least one piezoelectric element structure (5a; 5n', 5b ^' ) of at least one further piezoelectric element structure (5b; 5a ^' ), which in turn is suitable for expanding through said energy supply against the direction of oscillation and for generating a defined counter-pulse or a defined counter-force to reduce the original oscillation amplitude.

9. The device according to claim 8, characterized in that ^" that ^" the piezoelectric element structures (5a, 5b ... 5n; 5a ', 5b' ... 5n ^' ) in each case by one or more discrete piezoelectric elements in the form of quartz elements a plurality of discrete piezo elements in the form of quartz elements and / or by one or more quartz films are formed as a thick layer.

10. Device according to one of claims 8 and 9, characterized in that the electrically interconnected Piezoelement- structures (5a, 5b, 5n ', 5a ^' , 5b ^' ) seen in the direction of vibration are arranged side by side or one above the other or layered.

11. Device according to one of claims 8 to 10, characterized in that the electrically interconnected Piezoelement- structures (5a, 5b, 5n ', 5a ^' , 5b ^' ) are arranged immediately adjacent or spaced from each other.

12. Device according to one of claims 8 to 11, characterized in that the electrically interconnected Piezoelement- structures (5a, 5b) via at least one electronic component (8) ^"are connected, which is adapted to delay the counter-pulse in time.

13. The device according to claim 12, characterized in that the at least one electronic component (8) by at least one diode or a suitable other, the temporal sequence of the counter-pulse influencing electronic component (8) is formed.

14. The device according to one of claims 8 to 13, characterized in that the by the said energy supply against the oscillation direction expanding piezoelectric element structure (5a ^' ) is designed physically such that the counter-pulse is delayed in terms of its time-lapse sequence.

15. Device according to claim 14, characterized in that the piezoelectric element structure (5a ^' ) extending in the direction of expansion, as seen in the expansion direction, is dimensioned shorter than the piezoelectric element structure (5n', 5b ') generating electrical energy by deformation.

16. The device according to one of claims 8 to 15, characterized in that the electrical energy generated by deformation piezoelectric element structure (5a) is associated with at least one electronic component (9) for converting electrical energy into heat energy.

17. The device according to claim 16, characterized in that the at least one electronic component (9) for converting electrical energy into thermal energy by an electrical resistance or an inductance generating electronic component (9) is formed.

18. Device according to one of claims 12 to 17, characterized in that the degree of delay of the counter-pulse is set or selected so that the generated counter-pulse is effective shortly before reaching the maximum vibration of the machine or other component (1).

19. Device according to one of claims 8 to 18, characterized in that the machine or other components (1) bearing components Rotativlagern or linear bearings, massive components such as oil pan, engine block, engine mount and the like and / or surface components, such as panels, formwork panels , Cowling parts, body parts, window panes u. Like. On machines and equipment, especially on vehicles and / or aircraft of all kinds.