WO2000053954A1

WO2000053954A1 - Belt tensioning device with vibration damper

Info

Publication number: WO2000053954A1
Application number: PCT/EP2000/001155
Authority: WO
Inventors: Bernd Hartmann
Original assignee: INA Wälzlager Schaeffler oHG
Priority date: 1999-03-05
Filing date: 2000-02-12
Publication date: 2000-09-14
Also published as: DE19909684A1

Abstract

The invention relates to a tensioning device for belts, chains or the like, comprising a tensioning roller cooperating with a spring-loaded lever (1), wherein the lever (1) is connected to the torsional vibration damper having a housing (4) that contains damping means. Dividing walls (10) cooperating with the housing (4) and a pivoting body (7) that can pivot around the axis of rotation are mounted in said housing, wherein the pivoting body (7) has damping wings (8) which are disposed in-between the dividing walls (10). According to the invention, the damping wings (8) have at least one wing element (9a-9d) on their edges facing the housing (4 or 6) whose distance to the wall of the housing can be changed.

Description

Name of the invention

Belt tensioner with vibration damper

description

Field of the Invention

The invention relates to a tensioning device for belts, chains or the like with a tensioning roller or the like, which is operatively connected to a spring-loaded lever, the lever being connected to a torsional vibration damper which has a housing containing damping means in which with the Partition walls in operative connection and a rotating body pivotable about the axis of rotation are mounted, the rotating body having damping vanes which are arranged between the partition walls.

Background of the Invention

From the generic German patent specification 359 936 a belt tensioning device with a torsional vibration damper is known, which has a fixed housing in which a rotating body with damping vanes is rotatably mounted on a shaft, the damping vanes being guided in the housing and with partitions attached to the housing the damping oil in the housing is operatively connected. Adjustable valves are arranged in the partition walls, which control a channel from one side to the other of the partition walls. Occurring oscillating movements of the tension roller are transmitted via a lever and the shaft wedged to the rotating body, so that the damping vanes during their pivoting movement damping oil through the channels and the valves of the Pump one side to the other side of the partition walls and thereby dampen the movement hydraulically. The proposed damper is expensive to manufacture, in particular because of the channels and the adjustable valves in the partition walls, and moreover requires a specific individual adaptation. It is therefore not suitable for mass production.

From EP-0 120 069 B1 a belt tensioning device with a torsional vibration damper is known, in which a torsional vibration damper equipped with damping vanes is also installed. The damping vanes have a circumferential groove in which an essentially U-shaped seal is inserted. Furthermore, the partitions have sealing strips at their ends facing the rotating body, so that the damping spaces are sealed. However, since a certain displacement of damping means from one side of the damping wings to the other side or from one side of the partition walls to the other side is required to damp the oscillating movement of the rotating body with the damping vanes, the seal must have a certain permeability for the damping means, so that a long service life is not to be expected and the damping effect changes relatively quickly. In addition, the groove-shaped milling on the edges of the damping wings and the partition walls is complex to manufacture. This also applies to the additional and, as far as the seals of the damping wings are concerned, to their special preformed design.

Object of the invention

The object of the invention is to avoid the shortcomings of the known solutions and to provide a tensioning device for belts, chains or the like, the torsional vibration damper of which can be easily manufactured, is wear-resistant and moreover has variable damping. Summary of the invention

The object of the invention is achieved in that the damping vanes have at least one wing element on their edges facing the housing or inner housing, the distance of which from the housing wall can be changed. This configuration changes the gap between the damping vanes and the housing, so that the flow cross section for the damping means changes and thus the damping effect of the torsional vibration damper varies. Characterized in that the change in distance is caused by a deformation of the damping vanes and / or the wing elements depending on the increase in the damping medium pressure, it is achieved that at fast, i.e.. strong swinging movements of the tension pulley there is a stronger damping because the flow cross-section is reduced accordingly. The torsional vibration damper therefore adapts itself automatically to the damping requirements without special settings or the like being required for this.

Further refinements of the invention are the subject of subclaims 3 to 8.

The fact that the wing elements are firmly connected to the damping wings or are produced in one piece with them results in a stable unit and the required deformation can extend both to the wing element and to the damping wing, so that no excessive peak loads occur and without big problems durability is guaranteed. The wing elements are arranged on at least one side edge of a damping wing, preferably on both sides, and / or on the outer radial edge of the damping wing. The wing elements are preferably surfaces which, starting from the edges, are bent in the direction of rotation of the rotating body. They can be arranged only in one direction of rotation of the rotating body and also in both directions of rotation, that is to say on both sides of the damping vanes. Is caused by a swinging movement of the tension pulley, the lever of the torsional vibration damper rotated, which leads to a pivoting of the rotating body with the damping vanes in the housing, a pressure builds up on the front of the damping vanes, which leads to a bending of the damping vanes and / or a bending and pivoting of the wing elements, so that these with their Approach the free end of the housing wall and reduce the flow gap. If the wing elements are only arranged on one side of the damping wings, the gap reduction described above occurs when the torsional vibration and thus the rotation of the rotating body takes place in the direction of the wing elements, whereas the gap is not reduced in the opposite direction, but depending on the design the damping wing is enlarged by bending the gap. This can result in increased damping, for example in the direction in which the tensioning roller causes a reduction in the belt tension, while in the opposite direction caused by the spring which is operatively connected to the lever, the belt is quickly tensioned.

If the damping vanes and / or the dividing walls are arranged inclined in the direction of rotation, the effect described above can be further increased in that both the wing elements and the dividing walls or on their dividing wall extensions, depending on the pressure load, reduce or enlarge the Create gaps between the wing elements and the housing and the partitions or the partition extensions and the rotating body.

Brief description of the drawing

Show it:

1 shows a section through a tensioning device and a torsional vibration damper according to the invention parallel to

Axis of rotation,

Figure 2 shows a section along the line INI in Figure 1 by the Torsional vibration damper,

Figure 3 shows a section along the line III-III in Figure 1 through the

Torsional vibration damper,

FIG. 4 shows a section along line IV-IV in FIG. 1 through the torsional vibration damper,

5 shows a section along the line V-V in FIG. 2 through the torsional vibration damper,

6 shows a section through the torsional vibration damper along the line VI-VI in FIG. 1,

Figure 7 is a side view of a damping wing according to the

Arrow VII in Figure 6 and

8 shows a section along the line VIII-VIII in Figure 7 by a damping wing.

Detailed description of the drawing

In Figures 1 to 8, as far as shown in detail, 1 denotes a lever on which, not shown, a tensioning roller, a chain wheel or a tensioning rail acts directly or indirectly. The lever 1 is rotatably mounted on a shaft 2 and is biased in one direction of rotation by means of a torsion spring 3. The torsion spring 3 is supported on the other hand on a housing 4 in which the shaft 2 is also mounted. The housing 4 has an outer housing 5 and an inner housing 6, into which the shaft 2 extends. The inner housing 6, which also has a slide bearing for the shaft, is tightly closed, the passage of the shaft in the area of the outer housing 5 being sealed by sealing rings. On the shaft 2 inside the housing 4, in particular the inner housing 6, a rotating body 7 is arranged in a rotationally fixed manner, in particular wedged or fastened by means of a toothed hub profile. The rotating body 7 has two damping vanes 8 which, as in particular FIGS. 2, 3 and

6 can be seen, extend radially in the direction of the housing inner wall. Wing elements 9a to 9d are attached to the damping wings 8 and are located on the side edges or on the radially outer edge. Partitions 10 are attached to the housing 4 or inner housing 6 and extend in the direction of the shaft 2 to the rotating body 7.

The damping vanes 8 according to FIG. 2 have wing elements 9a on their outer radial edge, which are arranged clockwise and counterclockwise at approximately right angles to the damping vanes and are oriented essentially parallel to the housing wall. The partition walls 10 on the inner housing 6 form a gap to the rotating body, so that a certain amount of the damping means can escape from one side to the other of the partition wall when the rotating body is pivoted, and basic damping is thus achieved. If, due to a pivoting movement of the tensioning roller, the rotating body 7 is turned clockwise or counterclockwise, a pressure builds up in front of the respective side of the damping vanes 8, which depends on the speed of the pivoting movement. This pressure causes the damping wings 8 and the wing elements 9a to bend, so that the gap between the wing elements and the wall of the inner housing 6 is reduced and the damping effect increases. If the pivoting movement of the rotating body is slower or the deflection of the tensioning roller is less jerky, the deformation of the damping wings and the wing elements is less. If there is no deformation, the gap dimensions do not change.

In Figure 5, which shows an illustration according to the section V-V in Figure 2, are in particular the gaps between the partition 10 and the rotating body

7 and between the damping wing 8 and the wall of the inner housing 6 can be seen.

In the exemplary embodiment according to FIG. 3, the wing elements denoted by 9b are arranged on the outer edge of the damping wings 8 and point in a direction approximately at right angles from the damping wing into one Direction parallel to the housing wall. The partitions 10 are constructed in several parts and have a displaceable part wall part 10a, which can be moved radially to adjust the gap between the partitions and the rotating body. This enables a basic setting of the gap dimension and thus the damping. If, in the present exemplary embodiment, caused by a pivoting movement of the tensioning roller, the rotating body is rotated clockwise via the shaft, the damping wing and the wing element 9b are deformed by the pressure caused by the speed of the pivoting movement, so that the gap between the wing element 9b and the Wall shrinks and the damping effect is increased. If the tensioning roller pivots in the opposite direction and causes the rotating body to rotate in the counterclockwise direction, the damping vanes 8 deform in the corresponding direction, so that the gap depends on the speed of the pivoting movement of the tensioning roller and thus on the build-up of pressure between the wing elements 9b and the housing is enlarged.

In the exemplary embodiment according to FIG. 4, both the damping vanes 8 and the partition walls 10 are pivoted in the direction of rotation, so that the ends of the partition walls extend to the height of the rotating body 7. If the rotating body is rotated clockwise in this exemplary embodiment, not only the gap between the wing elements 9c and the inner housing 6 is reduced, but also the gap between the partition walls 10 and the rotating body 7, since the pressure build-up causes the ends of the partition walls to bend. Rotating the rotating body counterclockwise increases the column accordingly. Advantageously, the ends of the partition walls 10 facing the rotating body 7 are formed as laterally loose partition extensions so that they can move freely.

In the exemplary embodiment according to FIGS. 6 to 8, the damping wings 8, as can be seen in particular from FIGS. 7 and 8, have wing elements 9d on their side edges, the effect of which essentially corresponds to the wing elements 9a to 9c already described. Advantageously are the wing elements 9d plate-shaped, so that they extend from one side of the housing to the other side and are bent there. They can be welded, soldered or riveted to the main body of the damping wing. It makes sense to manufacture them from a different material, for example from plastic, if necessary.

LIST OF REFERENCE NUMBERS

lever

wave

Torsion spring

casing

Outer housing

Inner casing

Rotating body

Damping wing a wing element (Figure 2) b wing element (Figure 3) c wing element (Figure 4) d wing element (Figures 6 to 8) 0 partitions 0a movable partition part

Claims

claims

1. tensioning device for belts, chains or the like with a tension roller or the like, which is operatively connected to a spring-loaded lever (1), the lever (1) being connected to a torsional vibration damper which has a housing (4) containing a damping means, In the partition walls (10) that are operatively connected to the housing (4) and a rotating body (7) that can be pivoted about the axis of rotation are mounted, the rotating body (7) having damping vanes (8) that are located between the partition walls (10) in the housing ( 4), characterized in that the damping wings (8) have at their edges facing the housing (4) or inner housing (6) at least one wing element (9a to 9d), the distance to the housing wall is variable.

2. Clamping device according to claim 1, characterized in that the

Distance change to the housing wall by a deformation of the damping wing (8) and / or the or the wing elements (9a to 9d), the deformation follows the increase in the damping agent pressure.

3. Clamping device according to claim 2, characterized in that the

Wing elements (9a to 9d) are firmly connected to the damping wings (8) or are made in one piece with them.

4. Clamping device according to one of claims 2 or 3, characterized in that a wing element (9d) is arranged on at least one side edge of a damping wing (8).

5. Clamping device according to one of the preceding claims, characterized in that a flight element (9a to 9c) is arranged on the outer radial edge of at least one damping wing (8).

6. Clamping device according to one of the preceding claims, characterized in that on at least one side edge and / or the outer radial edge on both sides of the damping wing (8) seen in the direction of rotation, wing elements (9a) are provided.

7. Clamping device according to one of the preceding claims, characterized in that the partition walls (10) and / or the damping wings (8) are arranged inclined in the respective direction of rotation.

8. Clamping device according to claim 7, characterized in that the partitions (10) and / or arranged on these partition extensions with such a gap dimension to the rotating body (7) are arranged so that they approach this under pressure.