DE102009042297A1 - Balance shaft for series of three-cylinder stroke piston internal combustion engine or six-cylinder internal combustion engine, has side-cut which is normal to unbalance masses of unbalanced weight sections - Google Patents

Abstract

The balance shaft (1) has a side-cut which is normal to unbalance masses of unbalanced weight sections (2,2') in an area of an internal combustion engine middle portion (6). The balance masses of the unbalanced weight sections are flattened in the direction of a rotating surface (7) in the direction of the internal combustion engine middle portion.

Description

The invention relates to a balance shaft with the features of the preamble of claim 1.

It is based on the German patent specification DE 197 34 608 C1 out. In this a series of reciprocating internal combustion engines is described with a different number of cylinders. As a three-cylinder reciprocating internal combustion engine, this has a balance shaft, with two diametrically opposed unbalance weight sections and two bearings, wherein according to 3 between the bearings, the imbalance weight portions are formed by the balance shaft itself.

A disadvantage of such a generic balance shaft are their relatively high weight and the associated relatively high production costs.

For this reason, the present invention has the object, with less material use and virtually the same imbalance to represent a better imbalance / weight ratio.

This object is achieved by the feature in the characterizing part of patent claim 1.

The embodiment of the invention is advantageously a weight and cost savings of up to 15% possible. Furthermore, the mass moment of inertia about the axis of rotation is reduced, resulting in improved drive acoustics.

With the embodiments according to claims 2 and 3, the effect according to the invention improves again by up to 15%.

With the embodiment according to claim 4, the bending moments within the bearing points are significantly reduced.

The embodiment according to claim 5 is a particularly preferred embodiment.

Due to the low bending moments, the balance shaft according to claim 6 roller bearings, such. B. needle bearing.

In the following, the invention is explained in more detail with reference to a particularly preferred embodiment in three figures.

1 shows a side view of a balance shaft according to the invention.

2 shows a plan view, and a sectional plane BB through the balance shaft according to the invention.

3 shows a section BB 2 by the balance shaft according to the invention.

The following apply in the 1 to 3 the same reference numbers for the same elements.

1 shows a side view of a balance shaft according to the invention 1 , It is a balance shaft 1 for a series three-cylinder reciprocating internal combustion engine or a V-type six-cylinder internal combustion engine for a first-order torque compensation, preferably with a 90 ° cylinder angle. In this particularly preferred embodiment, two imbalance weight sections arranged diametrically opposite one another 2 . 2 ' on both sides of two bearings 3 . 3 ' arranged. The imbalance weight sections 2 . 2 ' are between the campsites 3 . 3 ' from the balance shaft 1 self-educated and outside the campsites 3 . 3 ' of corresponding, rectified additional masses 4 . 4 ' wherein the balance shaft is a drive element 5 outside the depository 4 which is a gear. In this particularly preferred embodiment, an imbalance weight portion 2 from the drive element 5 educated. An axis of rotation is with 7 quantified.

According to the invention, the balance shaft 1 in the area of an internal combustion engine center 6 normal to the imbalance weight sections 2 . 2 ' a sidecut on in 2 is recognizable. Next is out 1 removable, that the imbalance masses of imbalance weight sections 2 . 2 ' within the storage locations 3 . 3 ' in the direction of the engine center 6 in the direction of a rotation axis 7 are flattened. The flattening is on only one side of the balance shaft 1 symbolically represented by a triangle, which is a mass fraction with a small contribution to an unbalance moment M.

In another embodiment, the imbalance weight portions 2 . 2 ' also, as shown in the prior art, only within the bearing points 3 . 3 ' be arranged, but with the inventive design.

2 shows a plan view of the balance shaft 1 wherein the waist of the imbalance weight sections 2 . 2 ' in the area of the engine center 6 is clearly recognizable. The mass fraction with little contribution to the unbalance moment M is again only on one side of the balance shaft 1 represented symbolically by a triangle. Next is in 2 a sectional plane BB drawn, the corresponding section is in 3 shown.

3 shows the section BB 2 by the balance shaft according to the invention 1 overlooking the additional mass 4 ' , Cut shown is the shaft of the balance shaft 1 , Clearly visible in 3 is that the imbalance weight section 2 ' is formed roof-shaped on the side facing away from the imbalance mass. The mass fraction with little contribution to the unbalance moment M is symbolically represented on one side by a triangle. Of course, the roof-shaped formation also applies to the imbalance weight portion 2 ,

• 1. Masse der Ausgleichswelle 1 (links bzw. rechts von der Brennkraftmaschinenmitte 6 in Längsrichtung der Ausgleichswelle 1 betrachtet)
• 2. Schwerpunktabstand zur Rotationsachse Z_sp
• 3. Schwerpunktabstand zur Brennkraftmaschinenmitte 6 (in Längsrichtung der Ausgleichswelle 1 betrachtet) X_sp
• 4. Motordrehzahl ω

The balance shaft 1 According to the invention is carried out so that it also contributes to compensate for the total mass moment by their shape. The goal is that the quotient of unbalance moment / (mass of the balance shaft 1 ) reaches a maximum. For three-cylinder balance shafts or six-cylinder balance shafts of the V-type, preferably with a 90 ° cylinder angle, the unbalance moment of the balance shaft is calculated from the product of the following 4 factors:

• 1. mass of the balancer shaft 1 (left or right of the engine center 6 in the longitudinal direction of the balance shaft 1 considered)
• 2nd center of gravity distance to the axis of rotation Z_sp
• 3. Center of gravity distance to the engine center 6 (in the longitudinal direction of the balance shaft 1 considered) X_sp
• 4. Engine speed ω

m_ω

der Massenanteil der Welle (links bzw. rechts der Brennkraftmaschinenmitte 6),

Z_sp

der Schwerpunktabstand in Z-Richtung,

X-sp

der Schwerpunktabstand in X-Richtung und

ω

die Drehzahl ist.

Here, the unbalance torque [Nm] = m_ω · Z_sp · X_sp · ω ² , where

m_ω

the mass fraction of the shaft (left or right of the engine center 6 )

Z_sp

the center of gravity distance in the Z-direction,

X-sp

the center of gravity distance in the X direction and

ω

the speed is.

Mass fractions located near the axis of rotation or in the vicinity of the engine center 6 Thus, contribute very little to the balancing torque, ie the quotient of unbalance torque / (mass of the balancer shaft 1 ) is very low in this area.

In the 1 to 3 Thus it can be seen which mass fractions for an optimal ratio of unbalance torque / (mass of the balance shaft 1 ) can be omitted according to the invention. These areas, the mass fractions with little contribution to the unbalance moment M, are each symbolically represented by triangles and, of course, apply to both sides of the engine center 6 ,

Due to the inventive design of the balancer shaft 1 a lower material usage leads to practically the same unbalance and thus to a better unbalance moment / ratio (weight of the balance shaft) 1 ). Thus, a weight and cost savings of up to 30% is possible. Furthermore, the mass moment of inertia about the axis of rotation is reduced, which leads to a significantly improved drive acoustics. As a result of the inventive design, the bending moments in the bearings 3 . 3 ' are reduced, these can be stored on rollers, such. B. needle bearing.

LIST OF REFERENCE NUMBERS

1

balancer shaft

2, 2 '

Imbalance weight sections

3, 3 '

bearings

4, 4 '

additional materials

5

driving element

6

Engine center

7

axis of rotation

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19734608 C1 [0002]

Claims (6)

Balance shaft ( 1 ) for a series three-cylinder reciprocating internal combustion engine or a V-type six-cylinder internal combustion engine for a first-order torque compensation, with two imbalance weight sections (8) disposed diametrically opposite each other ( 2 . 2 ' ) and two storage locations ( 3 . 3 ' ), whereby between the depositories ( 3 . 3 ' ) the imbalance weight sections ( 2 . 2 ' ) from the balance shaft ( 1 ) are themselves formed, characterized in that the balance shaft ( 1 ) in the region of an internal combustion engine center ( 6 ) normal to imbalance masses of the imbalance weight sections ( 2 . 2 ' ) has a sidecut. Balance shaft according to claim 1, characterized in that the imbalance masses of the imbalance weight sections ( 2 . 2 ' ) in the direction of the engine center in the direction of a rotation axis ( 7 ) are flattened. Balancing shaft according to claim 1 or 2, characterized in that the imbalance weight sections ( 2 . 2 ' ) are formed roof-shaped on the side facing away from the imbalance mass. Balance shaft according to one of the claims 1 to 3, characterized in that the imbalance weight sections ( 2 . 2 ' ) on both sides of the bearings ( 3 . 3 ' ) and outside the storage locations ( 3 . 3 ' ) of corresponding, rectified additional masses ( 4 . 4 ' ) are formed. Balance shaft according to one of claims 1 to 4, wherein the balance shaft has a drive element outside of the bearing points, characterized in that an imbalance weight portion ( 2 ) of the drive element ( 5 ) is formed. Balancing shaft according to one of the claims 1 to 5, characterized in that the balancing shaft ( 1 ) is mounted in rolling bearings.

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