DE102005013135A1 - Reciprocating internal combustion engine comprises a crankshaft connected to differential shafts each having an unbalanced weight in which is integrated a torsional vibration damper - Google Patents

Abstract

Reciprocating internal combustion engine comprises a crankshaft connected to differential shafts (1, 1) each having an unbalanced weight (2, 2) in which is integrated a torsional vibration damper (3, 3). Preferred Features: The torsional vibration damper is a weight core (6, 6) embedded in a viscous material. The weight core is supported radially by a support element (7) which is made from a plastic or elastomer. The viscous material fills 50-99% of a space between the weight core and an inner wall of the weight. The viscous material has a viscosity of 10000-2000000 centistokes.

Description

The The invention relates to a reciprocating internal combustion engine having the features from the preamble of claim 1.

It is based on the European patent specification EP 1 063 447 B1 out. In this one equipped with an accessory and auxiliary equipment reciprocating internal combustion engine is described, serving as auxiliary units balancing shafts are in driving connection via a transmission with a crankshaft of the internal combustion engine. The counter-rotating driven balancing shafts are arranged substantially parallel to the crankshaft and geodesically below this. The transmission, in conjunction with the crankshaft and the auxiliary unit and the auxiliary units, a torsional vibration system for which a reliable torsional vibration damper is provided with perfect power transmission, which is arranged as a viscosity torsional vibration damper on at least one balance shaft.

adversely in the described embodiment, the increased space requirement for the viscous torsional vibration damper.

task The present invention is to show a measure, such as a A torsional vibration damper, or a torsional vibration damper for a Balancing shaft arrangement can be arranged to save space.

These The object is achieved by the feature in the characterizing part of the claim 1 solved by that the torsional vibration damper or the torsional vibration damper is integrated in the imbalance mass.

In Advantageously, it is through the inventive design possible, a torsional vibration damper or a torsional vibration damper in the balance shaft assembly to accommodate without this additional Required space requirements. Thus, rattle sounds avoided, without additional To introduce masses in the balance shaft assembly. Next can be elaborate, life-critical decoupling measures the balancing shaft arrangement omitted. Another advantage is the reduction of forces, in particular of alternating torques, in the drives of balance shafts to call.

A preferred embodiment is described in claim 2.

by virtue of the embodiment according to the claims 3 and 4, the mass element is (torsionally) elastic with respect to the centrifugal forces within supported the imbalance mass. At speed changes of Internal combustion engine is therefore advantageously not the Danger that the pig element hard against the inner wall of the imbalance mass hits. In one embodiment gem. Claim 7, with rolling elements as imbalance mass, additional end stops can be provided become.

The Measure of filling the space between the ground core and the inner wall of the imbalance mass according to claim 5 allows the active influence on the damping or eradication efficiency.

A preferred viscosity of the viscous material is according to claim 6 between 10,000 and 2,000,000 centistokes. The damping, or Tilgungsgrade are thus very precisely adjustable.

A further preferred embodiment is described claim 7. Due to the mobile design of the earth core, the effectiveness of a torsional vibration damper again elevated.

in the The following is the invention with reference to two preferred embodiments closer in two figures explained.

1 shows a section through a balance shaft assembly, perpendicular to a balance shaft axis;

2 shows a section through a balance shaft assembly, along the balance shaft axis.

1 shows a section through a balance shaft assembly perpendicular to a balance shaft axis 1a . 1'a , Two counter-rotating balance shafts 1 . 1' are aligned parallel to each other and largely parallel to a crankshaft, not shown, of a reciprocating internal combustion engine. The two balance shafts 1 . 1' are in a housing 8th stored, which has a flat surface 9 is connected to an unillustrated crankcase of the reciprocating internal combustion engine.

The balance shafts 1 . 1' each have an imbalance mass 2 . 2 ' on. Due to the cut through the balance shaft assembly is inside the imbalance masses 2 . 2 ' each a cut torsional vibration damper 3 . 3 ' recognizable sub Torsional damper also becomes a torsional vibration damper 3 ' Understood. The torsional vibration damper 3 is essentially one in a viscous material 5 embedded earth core 6 , the torsional vibration damper 3 ' is essentially one in an elastomer 5 ' embedded earth core 6 ' ,

As a viscous material 5 For example, silicone oil having a viscosity of between 10,000 and 2,000,000 centistokes may be preferably used, and other oils may be used. As elastomer 5 ' Rubber is preferably used. This may be, for example, NK (natural rubber) or NBR (acrylonitrile-butadiene rubber). The earth core 6 . 6 ' For example, it can be made of brass or ferrous materials, with a higher specific gravity than the unbalanced mass 2 . 2 ' be formed.

The earth core 6 . 6 ' is like in 2 shown, radially outward against the centrifugal force by a support element 7 , which is preferably a plastic element or an elastomeric element, supported. A striking of the earth's core 6 . 6 ' to an inner wall of the imbalance mass 2 . 2 ' at speed changes of the internal combustion engine, or when the engine is idling for example - because even then the constant idle speed is superimposed on rotational nonuniformity, which to a desired relative movement (damping, eradication) between the ground core 6 . 6 ' and the inner wall leads - is thus avoided. In the event that the ground core 6 is a rolling element, also not shown here end stops can be provided. In another embodiment, a storage of the roll-movable element can be provided on a bearing shoulder.

The embedding of the mass core 6 is for a torsional vibration damper 3 such that the ground core 6 inside the imbalance mass 2 always tangential easily movable. The tangential mobility is necessary so that in the viscous material 5 between the embedded earth core 6 and the inner wall of the imbalance mass 2 Shear forces are built up.

These shearing forces reduce the torsional vibrations. This effect can also be achieved by replacing a single earth core 6 a number of rolling bodies, preferably balls inside the imbalance mass 2 are arranged.

In the second embodiment as a torsional vibration damper 3 ' , is made by in elastomer 5 ' , embedded earth core 6 ' and the imbalance mass 2 ' creates a vibratory system. This spring mass vibration system is adjusted to the frequency of the rattle excitation of the balance shafts 1 . 1' coordinates and eliminates these. The effective frequency bandwidth of the torsional vibration damper 3 ' is compared to the effective range of the torsional vibration damper 3 much narrower and has the advantage that this can also be an open system.

The in the viscous material 5 occurring shear forces can be influenced by the choice of viscosity. The cavity between the embedded mass core 6 and the imbalance mass 2 is between 50% and 99% with the viscous material 5 filled. Due to the incomplete filling of the cavity with viscous material 5 Temperature fluctuations can be the imbalance mass 2 due to different thermal expansion coefficients of the different materials not to burst, since always compressible gases are included in the cavity.

In 2 for which the same reference numbers apply to the same components as in 1 , is a longitudinal section through a balance shaft axis 1a . 1b , shown for a generic balance shaft assembly. In 2 is in addition to the inventive design of the torsional vibration damper 3 ' a drive wheel 4 represented, via which the balance shaft assembly is driven directly or indirectly by the crankshaft.

By be the embodiment of the invention rales in a generic balance shaft assembly avoided without the weight of the balance shaft assembly by additional Masses, despite the introduction of a damper or absorber function, to enlarge. hereby become the forces and reduced torques in the drives of balance shaft assemblies. additionally can complicated, life-critical decoupling measures are avoided.

1, 1'

balancer shaft

1a, 1'a

Balancer shaft axis

2, 2 '

unbalanced mass

3, 3 '

torsional vibration dampers

4

drive wheel

5, 5 '

viscous Material / elastomer

6 6 '

dust core

7

supporting

8th

casing

9

mounting surface

Claims (7)

Reciprocating internal combustion engine with a crankshaft, which via a gearbox with counter-rotating balancer shafts ( 1 . 1' ) is in drive connection, each balance shaft ( 1 . 1' ) an imbalance mass ( 2 . 2 ' ) and is aligned substantially parallel to the crankshaft, wherein at least one balance shaft ( 1 . 1' ) with a torsional vibration damper ( 3 . 3 ' ), characterized in that the torsional vibration damper ( 3 . 3 ' ) in the imbalance mass ( 2 . 2 ' ) is integrated. Reciprocating internal combustion engine according to claim 1, characterized in that the torsional vibration damper ( 3 . 3 ' ) at least one in a viscous material ( 5 ) or in an elastomer ( 5 ' ) embedded ground core ( 6 . 6 ' ). Reciprocating internal combustion engine according to claim 1 or 2, characterized in that the mass core ( 6 . 6 ' ) at least radially by a support element ( 7 ) is supported. Reciprocating internal combustion engine according to claim 3, characterized in that the supporting element ( 7 ) is made of a plastic or an elastomer. Reciprocating internal combustion engine according to one of the aforementioned claims, characterized in that the viscous material ( 5 ) between 50% and 99% of a space between the mass core ( 6 ) and an inner wall of the imbalance mass ( 2 ). Reciprocating internal combustion engine according to one of the aforementioned claims, characterized in that the viscous material ( 5 ) has a viscosity between 10,000 and 2,000,000 centistokes. Reciprocating internal combustion engine according to one of the aforementioned claims, characterized in that the mass core ( 6 ) is rollable.