WO2007144240A2

WO2007144240A2 - Traction mechanism drive

Info

Publication number: WO2007144240A2
Application number: PCT/EP2007/054682
Authority: WO
Inventors: Michael Bogner; Frank Rettig
Original assignee: Schaefler Kg
Priority date: 2006-06-13
Filing date: 2007-05-15
Publication date: 2007-12-21
Also published as: WO2007144240A3; DE102006027353A1

Abstract

The invention relates to a traction mechanism drive, having a wraparound means, at least one driving rotating component and at least one driven rotating component, and a vibration absorber, having at least one absorber body which is rotatable about a rotational axis, and at least one absorber mass which is adapted to an excitation frequency and which is movable relative to the absorber body in at least one plane, during the movement of which absorber mass its radial spacing with respect to the rotational axis varies, wherein the vibration absorber comprises at least two absorber bodies (9, 10, 19, 20) with absorber masses, wherein the absorber bodies (9, 10, 19, 20) are assigned different rotating components.

Description

Description of the invention

traction drive

Field of the invention

The invention relates to a traction mechanism with a belt, at least one driving rotating component and at least one driven rotating component and a vibration damper, with at least one Tilgerkörper rotatable about a rotation axis and at least one tuned to an excitation frequency Tilgermasse with respect to the Tilgerkörpers in at least one Plane is displaced, their displacement changes their radial distance from the axis of rotation.

Background of the invention

Dynamic systems, which are excited in the range of their natural frequencies, generally show increased vibrations as a system response. When a system, such as a part of a rotating machine, is excited in a wide frequency spectrum, there is a risk that in unfavorable operating conditions resonance phenomena occur. In internal combustion engines, this is usually the case when natural frequencies of rotating components, for example, the timing drive, the unit operation, the camshaft or a camshaft adjuster, coincide with the excitation frequencies of the internal combustion engine. Since the excitation frequencies increase with the speed of the engine, they pass through the entire frequency range, in which natural frequencies of the mentioned components of the internal combustion engine are. These may be natural frequencies of a traction device in the aggregate mode or in the timing drive, as well as rotational frequencies of the aggregates or the timing gear. It is even possible to excite those degrees of freedom which do not have direct coupling with the combustion process, for example, bending vibrations of a vehicle body can arise which bring about a sound emission into the passenger compartment and the surroundings. These dynamic effects can lead to an increased load of traction means, in addition slip can occur or a sound radiation is generated in adjacent structures. These dynamic loads also reduce the life of the components and are therefore undesirable. In order to counteract these effects, hitherto elaborate countermeasures have been taken and mechanical and hydraulic clamping systems, freewheels, dampers or Elastriemen used. However, all known measures have disadvantages, hydraulic tensioning systems, for example, cause a loss of performance, which leads to increased fuel consumption, other measures lead to higher costs.

Vibration absorbers, in which a rotatable mass is movably connected to absorber masses, have been known for a long time, for example reference is made to CH 175420 or GB 379 165. Further vibration absorbers, which are intended for use in internal combustion engines, are known for example from DE 199 1 1 564 A1 or DE 100 59 101 A1. In the article "Speed Adaptive Tilger - An alternative for vibration reduction?" (ATZ Automobiltechnische Zeitschrift 103 (2001) 4, pp 290-296) various constructive embodiments of Schwingungstilgem for the drive train of a motor vehicle are described.

For the effect of the vibration absorber is sufficient, a certain absorber mass is required. Since the available installation space is limited today in internal combustion engines, the integration of the vibration damper in a traction drive is difficult.

Summary of the invention

The invention has for its object to provide a traction mechanism, in which the integration of a vibration absorber is facilitated. To solve this problem, it is provided according to the invention in a traction drive of the type mentioned that the vibration damper comprises at least two Tilgerkörper with absorber masses, wherein the Tilgerkörper are assigned to different rotating components.

By inventively provided division of the required total mass of the absorber masses on several Tilgerkörper the vibration damper can also be used in such Zugmitteltrieben in which the installation space is limited. The two individual absorber bodies are each significantly smaller than a single absorber body.

It is particularly advantageous if a Tilgerkörper is firmly connected to the associated rotating component or integrally formed therewith. The shape and structure of the rotating component can thus be matched exactly to the Tilgerkörper.

In the traction mechanism drive according to the invention, provision can also be made for the first absorber body to be tuned to a first excitation frequency and the second absorber body for a second excitation frequency and an optionally present further absorber body for a further excitation frequency. As a result, several engine orders can be paid in an internal combustion engine. For example, in a four-cylinder engine, the first engine order dominates, with the second Tilgerkörper could also be a side order, for example, the second engine order, be repaid. The oscillation of vibrations with two or more frequencies is not possible with a single absorber body or only with a very large construction effort. By inventively provided use of two or more Tilgerkörpern, which are tuned to a particular excitation frequency, but this is easily possible.

It can also be provided that the first Tilgerkörper is tuned to a frequency which is slightly below a fixed excitation frequency of a vibration order, wherein the second Tilgerkörper on a frequency is tuned which is slightly above the excitation frequency. This achieves an increase in the bandwidth of vibration damping. At the same time, the traction mechanism drive becomes less sensitive to wear and tolerances.

In the traction mechanism according to the invention the Tilgerkörper, the absorber masses and the radial distance of the absorber masses to the axis of rotation are respectively determined such that the vibration damper behaves like a vibration absorber comprising only one Tilgerkörper. As a result, the same effect as with a single conventional Tilgerkörper is achieved, which at the same time give the mentioned advantages in terms of installation space.

In the traction mechanism according to the invention, it is particularly preferred that the vibration damper is installed or mounted in or on a pulley, a pulley, a roller of an aggregate, as well as in or on a camshaft, a camshaft pulley or a phaser. In principle, the vibration damper can be on or attached to all rotating components of an internal combustion engine.

In addition, the invention relates to a traction mechanism drive, in particular a traction mechanism drive of the type described, with a belt, at least one driving rotating component and at least one driven rotating component and a vibration absorber, with at least one about an axis rotatable Tilgerkörper and at least one, to an excitation frequency matched absorber mass, which is displaceable with respect to the Tilgerkörpers in at least one plane at the displacement of which changes their radial distance from the axis of rotation.

In the traction mechanism according to the invention the belt is formed as Elastriemen.

Eel straps, which are known per se, take over both the function of the belt and the function of a tensioning device. This can be done on one conventional tensioning device are dispensed with, resulting in considerable cost advantages.

In the traction drive according to the invention, it is particularly preferred that the product of the modulus of elasticity and the cross-sectional area of the Elastriemens 10,000 N to 150,000 N, in particular 20,000 N to 120,000 N is.

The traction mechanism according to the invention may be part of a drive train, a unit operation or a timing drive of an internal combustion engine, wherein the traction mechanism drive preferably does not have a separate clamping device and the generation of the voltage takes place substantially solely by the Elastriemen.

Brief description of the drawings

Further advantages and details of the invention are described below with reference to embodiments with reference to the figures. The figures are schematic representations and show:

1 shows a conventional traction mechanism drive with a vibration damper.

2 shows a traction mechanism according to the invention with two separate Tilgerkörpern. and

Fig. 3 shows a traction mechanism according to the invention with a Elastriemen.

Fig. 1 shows a conventional traction drive with a vibration damper.

The traction mechanism drive 1 comprises a driving roller 2 and a plurality of driven rollers. A driven roller 3 is connected to the generator of an internal combustion engine. Another roller 4 is connected to the water pump. A deflection roller 1 1 is acted upon by a schematically illustrated clamping element 5, in the traction drive 1, the components over a belt 6 are connected together to produce the required voltage. On the roller 3, a vibration damper 7 is mounted, which is shown only schematically and has movable absorber masses in its interior, the distance to the axis of rotation changes depending on the rotational speed. The absorber masses are tuned to a certain speed and thus to a certain vibration frequency. In the case of an undesirable speed change, the radial distance of the absorber masses from the axis of rotation changes, so that the disturbing oscillation is eliminated. As shown in FIG. 1, however, the vibration absorber 7 requires a large installation space.

Fig. 2 shows a traction mechanism according to the invention with two separate Tilgerkörpern.

The traction mechanism 8 includes in accordance with the traction mechanism shown in Fig. 1 a driving roller 2 and other rollers or discs, which are connected to each other via the belt 6. At the roller 3 connected to the generator, a vibration damper is arranged with a Tilgerkörper 9, another Tilgerkörper 10 is connected to the roller 4, which is coupled to the water pump of the internal combustion engine. As can be seen in FIGS. 1 and 2, the absorber bodies 9, 10 are smaller than the individual absorber body of the vibration absorber 7, so that they can be integrated more easily even in confined spaces in the engine compartment of a motor vehicle. The two absorber bodies 9, 10 have absorber masses, which are not shown in more detail, which eliminate unwanted vibrations. Here, the Tilgerkörper, the absorber masses and the distances of the absorber masses to the rotation axis are chosen so that the two Tilgerkörper 9, 10 achieve the same effect as the individual vibration absorber 7.

In alternative embodiments, the Tilgerkörper 9, 10 may also be designed so that a Tilgerkörper is tuned to a frequency which is slightly lower than the excitation frequency, the other Tilgerkörper can be tuned to a slightly higher frequency. In this case, the bandwidth of the erased vibrations greater, the Tilgerwirkung is then ensured even with larger structural tolerances and the presence of wear.

There are also other modifications possible in which the Tilgerkörper 9, 10 are each tuned to a separate excitation frequency. The first absorber body can be matched to the first engine order of the internal combustion engine, the second absorber body can be matched to the second engine order.

Fig. 3 shows a traction mechanism drive with a Elastriemen.

The traction drive 12 comprises a driving roller 13, which is connected to the crankshaft of an internal combustion engine, a plurality of driven rollers, wherein a roller 14 with an air conditioner, a roller 15 with a generator, a roller 16 connected to a water pump and a roller 17 as a pulley is trained. The individual components of the traction mechanism drive 12 are connected to each other via a Elastriemen 18. It is essential that the traction mechanism drive 12 does not require a separate clamping element such as a spring tensioner or a hydraulic tensioner. The required belt force and belt tension is generated solely by the elastic strap 18. The product of the cross-sectional area of the Elastriemens and its modulus of elasticity is typically 20,000 N to 120,000 N. The guide roller 17 and connected to the generator roller 15 each have a Tilgerkörper 19, 20 on. The structure and the effect of the Tilgerkörper 19, 20 corresponds to the Tilgerkörpern 9, 10 shown in FIG.

reference numerals

1 traction drive

2 roll

3 roll

4 roll

5 clamping element

6 straps 7 vibration absorber

8 traction drive

9 absorber body

10 absorber body 11 guide roller

12 traction drive

13 roll

14 roll

15 roll 16 roll

17 roll

18 Elastic belt

19 absorber body

20 absorber body

Claims

claims

1. traction mechanism drive, with a belt, at least one driving rotating component and at least one driven rotating rieenden component and a vibration damper, with at least one rotatable about a rotational axis Tilgerkörper and at least one tuned to an excitation frequency absorber mass with respect to the Tilgerkörpers in at least one Plane is displaced, their displacement changes their radial distance from the axis of rotation, characterized in that the vibration damper at least two Tilgerkörper

(9, 10, 19, 20) with absorber masses, wherein the Tilgerkörper (9, 10, 19, 20) are associated with different rotating components.

2. traction mechanism according to claim 1, characterized in that a TiI- gerkörper (9, 10, 19, 20) fixedly connected to the associated rotating component or integrally formed therewith.

3. traction drive according to claim 1 or 2, characterized in that the first Tilgerkörper (9, 19) is tuned to a first excitation frequency and the second Tilgerkörper (10, 20) to a second excitation frequency and an optionally existing further Tilgerkörper to a further excitation frequency ,

4. traction mechanism according to one of the preceding claims, character- ized in that the first Tilgerkörper (9, 19) is tuned to a frequency which is slightly below a fixed excitation frequency of a vibration order, wherein the second Tilgerkörper (10, 20) on a Frequency is tuned, which is slightly above the excitation frequency.

5. traction mechanism according to one of the preceding claims, characterized in that the Tilgerkörper (9, 10, 19, 20), the absorber masses and the radial distance of the absorber masses to the axis of rotation in each case such fixed are set, that the vibration damper behaves like a vibration damper comprising only one Tilgerkörper.

6. Traction drive according to one of the preceding claims, character- ized in that the vibration damper in or on a pulley, a pulley, a roller (2, 3, 1 1, 13 - 17) of an aggregate, a camshaft, a camshaft pulley, a Camshaft adjuster is installed or attached.

7. traction mechanism drive, in particular according to one of claims 1 to 6, with a belt, at least one driving rotating component and at least one driven rotating component and a vibration damper, with at least one rotatable about a rotational axis Tilgerkörper and at least one tuned to an excitation frequency absorber mass, which is displaceable with respect to the absorber body in at least one plane, whose displacement changes its radial distance from the axis of rotation, characterized in that the wrapping means is designed as Elastriemen (18).

8. traction drive according to claim 7, characterized in that the product of the modulus of elasticity and the cross-sectional area of the Elastriemens (18) is 10,000 N to 150,000 N, in particular 20,000 N to 120,000 N.

9. traction drive according to claim 7 or 8, characterized in that it does not have a separate clamping device and the generation of the voltage substantially solely by the Elastriemen (18).

10. Traction drive according to one of the preceding claims, character- ized in that it is part of a drive train, a unit operation or a timing drive of an internal combustion engine.