DE102017004126B4 - Torsional vibration damper - Google Patents

Abstract

Torsional vibration damper (10; 20), in particular for damping torsional vibrations of an internal combustion engine, with a housing (11; 21) which has at least a first chamber (12; 22) and a second chamber (14; 24), wherein
a1) a first secondary mass (13; 23), which is in contact with the housing (11; 21) via a first viscous liquid arranged in the first chamber (12; 22), is arranged in the first chamber (12; 22); and
a2) a second secondary mass (15; 25), which is in contact with the housing (11; 21) via a second viscous liquid arranged in the second chamber (14; 24), is arranged in the second chamber (14; 24); and
b) the at least one first chamber (12; 22) and the second chamber (14; 24) are not fluidly connected to one another,
wherein the secondary masses (13; 15; 23; 25) extend in their respective chambers around an axis of rotation (1) of the torsional vibration damper; and
wherein the secondary masses (13; 15; 23; 25) are each designed in the shape of a circular ring; and
wherein the secondary masses (23, 25) in the housing (21) are arranged radially offset from one another.

Description

The invention relates to a torsional vibration damper, in particular for damping torsional vibrations of an internal combustion engine.

Reciprocating piston machines in the form of internal combustion engines convert the driving linear movement of the pistons into rotary movements using crankshafts and thus generate a usable drive. In addition to the rotational irregularity, ignition in the cylinder with its gas and subsequent mass forces leads to a shock on the crankshaft, so that it twists slightly at that point. This then leads to natural torsional vibrations of the crankshaft. Due to the regularity of the torsional vibration excitations, under certain conditions resonance peaks can occur, which can lead to component failure. In order to reduce such resonance increases within the engine, torsional vibration dampers, also known as torsional vibration absorbers, are used.

So-called rubber torsional vibration dampers are known with a primary mass (hub) that is torsionally rigidly connected to the system to be damped (e.g. crankshaft, camshaft) and a secondary mass (damper mass) that is elastically connected to the primary mass by means of a rubber spring element. Rubber dampers have so far been considered sufficient e.g. B. considered for ordinary 4-cylinder car engines. As the performance of such engines increases, there is a need for more powerful vibration dampers, especially in diesel engines, without requiring additional installation space.

An alternative to the rubber damper is the so-called viscosity damper, in which the secondary mass (seismic mass) is freely rotatable in a primary mass housing. A gap between the housing and the secondary mass is filled with a highly viscous liquid (e.g. silicone oil). The shear flow induced by torsional vibrations dissipates mechanical power, giving the viscosity damper a high damping effect, which enables it to be used even on large engines. When using silicone oil, the non-Newtonian effects of the liquid are also used, which lead to a spring coupling of the secondary side, so that the vibration damper can also be tuned to the torsional natural frequency of the crankshaft, which leads to an overall better efficiency of the vibration damper.

The DE 10 2004 060 754 A1 discloses, for example, a viscosity damper, with a plurality of secondary masses which are arranged in the housing and are each coupled to the housing via the viscous fluid for vibration technology. Here, at least one spacer must be arranged between two secondary masses arranged next to one another, which is connected to the housing in a rotationally fixed manner. These spacers or partitions make the damper assembly complex and make it difficult to fill the damper housing with viscous liquid. In addition, the partitions and especially their fixation make the system more expensive.

Another viscosity damper with two secondary masses is from the DE 10 2012 107 554 A1 known, in which the at least two secondary masses are designed such that one of the two secondary masses extends at least in some areas radially outside the other secondary mass and is separated from the other secondary mass in this area by an axial gap. The disadvantage of this structure is that setting and/or adapting the damping effect is complex and difficult.

The document DE 10 2006 014 952 A1 discloses a vibration absorber, comprising at least one absorber body rotatable about an axis of rotation and at least one absorber mass tuned to an excitation frequency, the absorber mass being displaceable with respect to the absorber body in at least one plane, the displacement of which changes its radial distance from the axis of rotation.

document US 2,585,382 A discloses a device for reducing torsional vibrations of rotating shafts, such as the crankshafts of engines.

document US 3,121,347 A discloses a viscous torsional vibration damper in which the shear strength of a viscous fluid between the closely spaced opposing surfaces of one or more flywheels and a flywheel housing is used as a compliant coupling between the opposing flywheel and housing surfaces.

document DE 693 05 988 T2 apparently a method and a device for compensating for an imbalance, specifically a method and a device for dynamically compensating for an imbalance in a rotating body.

It is an object of the invention to further develop the known prior art in order to provide a torsional vibration damper with which disadvantages of conventional techniques can be avoided. The object of the invention is, in particular, to provide a torsional vibration damper deliver, the damping effect of which can be easily adjusted and/or adapted.

These tasks are solved by a torsional vibration damper with the features of the independent claim. Advantageous embodiments and applications of the invention are the subject of the dependent claims and are explained in more detail in the following description with partial reference to the figures. The torsional vibration damper is also referred to below as a vibration damper or damper.

According to general aspects of the invention, a torsional vibration damper is provided, in particular for damping torsional vibrations of an internal combustion engine, e.g. B. Torsional vibrations of a crankshaft or camshaft of the internal combustion engine. The torsional vibration damper is a viscosity damper. The torsional vibration damper includes a housing that has at least a first chamber and a second chamber. Here, a first secondary mass is arranged in the first chamber, which is in contact with the housing via a first viscous liquid arranged in the first chamber. Furthermore, a second secondary mass, which is in contact with the housing via a second viscous liquid arranged in the second chamber, is arranged in the second chamber. Furthermore, the at least one first chamber and the second chamber are not fluidly connected to one another. The at least two secondary masses are therefore each accommodated in their own, separate chamber, which is not in fluid communication with another chamber.

A particular advantage of the torsional vibration damper is that the different chambers can be filled with different viscous liquids. In this way, the damping effect can be adjusted in a simple and very targeted manner using the different viscous liquids. This makes particularly precise and easy-to-use frequency tuning possible, even for different drive train configurations.

For example, the first and second viscous liquid can be different, in particular the first viscous liquid can have a different viscosity than the second viscous liquid. By choosing the viscous liquid, in particular by varying the viscosity, the damping effect of the torsional vibration damper can be adjusted precisely and easily. The viscous liquids in the chambers can also be the same. The viscous liquid can in particular be a viscoelastic liquid, e.g. B. silicone oil or another liquid.

According to a preferred embodiment, the housing comprises exactly two chambers, with a secondary mass being arranged in each of the chambers. However, the torsional vibration damper is not limited to this, but can have more than two chambers and more than two secondary masses. According to an alternative embodiment, the housing therefore has at least one further chamber which is not fluidly connected to another chamber of the housing which has a secondary mass and in which a secondary mass is arranged which communicates with the housing via a viscous liquid arranged in the further chamber Contact is.

The at least one first chamber and a second chamber are preferably integrated into the same housing part, preferably into a one-piece housing part. The at least one first chamber and a second chamber are preferably integrated into a housing part that only has one connection point, e.g. B. a hub, for the rotationally fixed attachment of the torsional vibration damper or housing on a shaft, in particular the crankshaft, of the internal combustion engine.

The secondary masses can extend in their respective chambers around an axis of rotation of the vibration damper. The torsional vibration damper and/or the housing, the chambers and the secondary masses can be essentially rotationally symmetrical to the axis of rotation of the damper.

According to an advantageous embodiment, the secondary masses can each be designed in the shape of a circular ring, preferably with different sizes. The term “ring-shaped” should in particular also include flat ring shapes, i.e. H. Ring shapes with lower and upper plan sides. According to a further aspect, the secondary masses can have different weights.

According to one embodiment variant, the secondary masses in the housing can be arranged axially offset from one another. This means that the secondary masses are arranged offset in the direction of the axis of rotation of the vibration damper.

According to one embodiment variant, the secondary masses in the housing can be arranged radially offset from one another.

The invention further relates to a motor vehicle, in particular a commercial vehicle, with a Torsional vibration damper as described in this document.

• 1 einen axialen Querschnitt durch einen Drehschwingungsdämpfer gemäß einer bevorzugten Ausführungsform der Erfindung; und
• 2 einen axialen Querschnitt durch einen Drehschwingungsdämpfer gemäß einer weiteren bevorzugten Ausführungsform der Erfindung.

The previously described preferred embodiments and features of the invention can be combined with one another in any way. Further details and advantages of the invention are described below with reference to the accompanying drawings. Show it:

• 1 an axial cross section through a torsional vibration damper according to a preferred embodiment of the invention; and
• 2 an axial cross section through a torsional vibration damper according to a further preferred embodiment of the invention.

Identical or functionally equivalent elements are designated with the same reference numerals in all figures.

1 shows an axial cross section through a torsional vibration damper 10 according to a preferred embodiment of the invention.

The torsional vibration damper is in 1 generally designated 10. This torsional vibration damper initially has a housing 11 (primary mass), which is provided radially on the inside with a hub area (not shown), which, depending on the installation situation, is either disk-shaped and provided with fastening openings 4, as shown, or with a bush-like hub-shaped area for sliding on a shaft 2. In the present case, the shaft 2 is a crankshaft 2 of a reciprocating internal combustion engine. The central axis of the crankshaft is designated by reference number 1. The central axis 1 determines the axial direction. The radial direction is perpendicular to this.

The housing 21 of the torsional vibration damper 10 is designed in cross section such that it has a region of greater thickness in the axial direction in the radially outer region. In this area, the housing forms two separate chambers or cavities 12 and 14. There is a secondary mass 13, 15 in each of the chambers. Each chamber 12, 14 is also filled with a viscous liquid (viscous liquid), e.g. B. silicone oil.

By way of example only, the torsional vibration damper 10 can be manufactured in such a way that the secondary mass 13 or 15 is first introduced into the open chamber 12 or 14, which is not yet closed with a cover part. Then the chambers 12 and 14 are each closed (for example welded) with a cover part (not shown). The chambers 12 and 14 are then filled with the viscous liquid through one or more filling openings (not shown). The filling opening or openings are then closed.

The two chambers 12 and 14 are not fluidly coupled to one another, i.e. i.e., viscous fluid from one chamber cannot reach the other chamber.

The viscous liquid causes a force coupling of the secondary masses 12 or 15 to the housing 11, whereby the torsional vibrations of the shaft 2 are effectively dampened.

In the exemplary embodiment 1 the two chambers 12 and 14 are arranged axially offset from one another. As a result, the secondary masses 13, 15 in the two chambers 12, 14 are also arranged axially offset from one another.

When in 1 In the exemplary embodiment shown, the two secondary masses 13 and 15 are designed in the shape of a circular ring, but are designed with different ring thicknesses in the radial direction and therefore with different weights.

2 shows an axial cross section through a torsional vibration damper 20 according to another preferred embodiment of the invention.

This torsional vibration damper 20 initially has a housing 21 (primary mass), which is again designed in cross-section so that it has an area of greater thickness in the axial direction in the radially outer area. In this area, the housing 21 forms two separate chambers or cavities 22 and 24. There is a secondary mass 23, 25 in each of the chambers. Each chamber 22, 24 is also filled with a viscous liquid (viscous liquid), e.g. B. silicone oil. The two chambers 22 and 24 are not fluidly coupled to one another, i.e. i.e., viscous fluid from one chamber cannot reach the other chamber.

The peculiarity of the in 2 The embodiment shown is that the two chambers 22 and 24 and thus also the secondary masses 23, 25 arranged therein are arranged radially offset from one another. The two secondary masses 13 and 25 are again designed in the shape of a circular ring, but with different ring thicknesses in the radial and axial directions and with different diameters.

It was already mentioned above that the torsional vibration damper also had more than two came mers and can have more than two secondary masses.

Although the invention has been described with reference to specific embodiments, it will be apparent to those skilled in the art that various changes may be made and equivalents substituted without departing from the scope of the invention. Accordingly, the invention is not intended to be limited to the embodiments disclosed, but is intended to include all embodiments that fall within the scope of the appended claims. In particular, the invention also claims protection for the subject matter and features of the subclaims, regardless of the claims referred to.

Reference symbol list

1

Central axis of the crankshaft

2

crankshaft

10

Torsional vibration damper

11

Housing

12

First chamber

13

First secondary mass

14

Second chamber

15

Second secondary mass

20

Torsional vibration damper

21

Housing

22

First chamber

23

First secondary mass

24

Second chamber

25

Second secondary mass

Claims (6)

Torsional vibration damper (10; 20), in particular for damping torsional vibrations of an internal combustion engine, with a housing (11; 21) which has at least a first chamber (12; 22) and a second chamber (14; 24), wherein a1) a first secondary mass (13; 23), which is in contact with the housing (11; 21) via a first viscous liquid arranged in the first chamber (12; 22), is arranged in the first chamber (12; 22); and a2) a second secondary mass (15; 25), which is in contact with the housing (11; 21) via a second viscous liquid arranged in the second chamber (14; 24), is arranged in the second chamber (14; 24); and b) the at least one first chamber (12; 22) and the second chamber (14; 24) are not fluidly connected to one another, wherein the secondary masses (13; 15; 23; 25) extend in their respective chambers around an axis of rotation (1) of the torsional vibration damper; and wherein the secondary masses (13; 15; 23; 25) are each designed in the shape of a circular ring; and wherein the secondary masses (23, 25) in the housing (21) are arranged radially offset from one another. Torsional vibration damper Claim 1 , wherein the first and second viscous liquid are different, in particular have a different viscosity. Torsional vibration damper (10; 20). Claim 1 or 2 , wherein the housing (11; 21) has at least one further chamber (14; 24) which is not fluidly connected to another chamber (12; 22) of the housing (11; 21) which has a secondary mass and in which a secondary mass (15; 25) is arranged, which is in contact with the housing (11; 21) via a viscous liquid arranged in the further chamber (14; 24). Torsional vibration damper (10; 20) according to one of the preceding claims, wherein the secondary masses are each designed with different sizes. Torsional vibration damper (10; 20) according to one of the preceding claims, wherein the secondary masses (13; 15; 23; 25) have a different weight. Motor vehicle, in particular commercial vehicle, with a torsional vibration damper (10; 20) according to one of the preceding claims.

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