DE102016210480B4 - Method of manufacturing a mass balance shaft and mass balance shaft produced therefrom - Google Patents

Abstract

Method for producing a mass balance shaft (1) for a reciprocating internal combustion engine, with a mass balance weight (2) and at least two bearing sections (4, 4'), which are formed by bearing rings (3, 3') and have a first inner diameter D1, wherein the balancing weight (2) has recesses (4) running radially outwards, into which the bearing rings (3, 3') can be inserted, with an end section (5, 5') of the balancing weight (2) extending as far as a bearing section (4, 4' ) has a smaller outer circumference D2 than the inner diameter D1, comprising the following method steps: - sliding the bearing ring (3, 3') over the end section (5, 5') up to the bearing section (4, 4') and - fixing the bearing ring ( 3, 3') in the bearing section (4, 4'), characterized in that the position of the bearing ring (3, 3') is fixed by a prestressed elastic element (6) between the bearing ring (3, 3') and the mass balance weight (2 ) he follows.

Description

The invention relates to a method for producing a mass balancer shaft having the features of patent claim 1 and a mass balancer shaft manufactured according to this and having the features of patent claim 2.

• - Lagerabschnitte, an denen Gleitlager angeordnet sind,
• - Gewichtsabschnitte, an denen Gegengewichte angeordnet sind,
• - Eine Längsbohrung in ungefähr axialer Richtung durch die Lagerabschnitte und Gewichtsabschnitte zur Versorgung der Gleitlager in den Lagerabschnitten mit Schmierflüssigkeit,
• - Die Längsbohrung ist exzentrisch zur Drehachse der Massenausgleichswelle angeordnet und
• - Die Mitte der Längsbohrung ist in Richtung der Gegengewichte versetzt angeordnet.

For the technical environment, for example, refer to the German Offenlegungsschrift DE 10 2004 011 820 A1 pointed out. A mass balance shaft for an internal combustion engine with the following features is known from this published application:

• - Bearing sections on which plain bearings are arranged,
• - weight sections on which counterweights are arranged,
• - A longitudinal bore in approximately axial direction through the bearing sections and weight sections for supplying the plain bearings in the bearing sections with lubricating fluid,
• - The longitudinal bore is arranged eccentrically to the axis of rotation of the mass balance shaft and
• - The center of the longitudinal bore is offset in the direction of the counterweights.

With this known mass balance shaft, a lighter mass balance shaft is presented, which is lighter with the same mass forces and moments generated without losing rigidity.

Another generic mass balance shaft is from the German Offenlegungsschrift DE 10 2013 200 237 A1 famous. This published application proposes a multi-part mass balance shaft for an internal combustion engine, which is mounted in a housing, the shaft body consisting of at least two shaped sheet metal layers and forming a cavity in at least two shaped sheet metal layers to accommodate at least one weight.

Even with this known mass balance shaft, the maximum possible mass saving has not yet been shown.

From the Japanese publication JP 2000-186 746 A Another mass balance shaft is known in which the mass balance weights and the bearing sections can be introduced into a longitudinally slotted hollow shaft.

Next is from the International Patent Application with International Publication Number WO 2006/072 118 A1 a balancer shaft unit for internal combustion engines is known for installation in a housing with non-split bearing sets, with at least one balancer shaft being in one piece with its at least one balancer weight. The balancer shaft unit is characterized in that at least one bearing of the balancer shaft is formed by a constriction of the balancer shaft as a bearing journal and by a split bearing ring fixed to the housing, the outer diameter of which is larger than the outer diameter of the balancer weight.

From the German Offenlegungsschrift DE 10 2012 217 407 A1 a balancer shaft for an internal combustion engine with at least one weight that generates an imbalance is known. It is essential to the invention that the balancing shaft is designed in such a way that at least two different operating points can be set with at least two different imbalance compensations. As a result, the balancer shaft can be flexibly adapted to different operating points.

From the WO 2011/012 239 A2 discloses a balance shaft for a single or multi-cylinder engine with at least one imbalance weight section and at least one bearing point that is assigned to the at least one imbalance weight section, with the bearing point having a radial peripheral surface that only partially extends over a circumference of the bearing point, so that a The centrifugal force resulting from rotation of the balancer shaft lies within an area of the bearing point that is formed by the peripheral surface that partially extends over the circumference of the bearing point, and with a raceway that surrounds the partially formed peripheral surface of the bearing point and by a force- and/or shape- and/or is connected to the bearing point by a material connection, the peripheral surface of the bearing point having a receiving area for receiving the raceway, and that at least one axially outer edge area or at least one annular area of the raceway has at least one contact surface of the receiving area is non-positively and/or positively and/or firmly connected.

$$\text{e}>1/2\left(\text{d}2-\text{d}1\right)$$

$$\text{e}<1/2\left(\text{d}2+\text{d}1\right)$$

mit
d1 = Außenhüllkreisdurchmesser des Unwuchtabschnitts und des Lagerabschnitts,
d2 = Innendurchmesser des Lagerrings,
e = Mittelpunktsversatz zwischen d2 und d1.From the German Offenlegungsschrift DE 10 2010 034 289 A1 On which the present invention is based, an unbalanced shaft is known for compensating inertial forces and/or moments of inertia of an internal combustion engine, with an unbalanced section whose center of mass runs eccentrically to the axis of rotation of the unbalanced shaft to generate the shaft unbalance, a bearing section adjoining the unbalanced section and a bearing section joined thereto Bearing ring, the outer lateral surface of which serves as a raceway for the rolling elements of a roller bearing that rotatably supports the unbalanced shaft and the inner lateral surface of which serves as an unbalanced bearing Direction extending bearing peripheral area jumps back radially compared to the outer enveloping circle of the unbalanced portion. The following geometric relationships are provided for the purpose of mounting the bearing ring on the bearing section: $$\text{i.e}2\ge \text{i.e}1$$

$$\text{e}>1/2\left(\text{i.e}2-\text{i.e}1\right)$$

$$\text{e}<1/2\left(\text{i.e}2+\text{i.e}1\right)$$

with
d1 = outer enveloping circle diameter of the unbalance section and the bearing section,
d2 = inner diameter of the bearing ring,
e = center offset between d2 and d1.

A disadvantage of this known balance shaft unit is the relatively complex assembly.

Mass balance shafts are generally, with a few exceptions, made in one piece. Especially in the case of mass balance shafts with roller bearings, these are forged from steel that is suitable for roller bearings. To reduce weight, there are patent applications and patents, for example, which save material in the unloaded area of the bearing.

Due to the production from one piece, the weight potential for reducing the mass of the mass balancing shaft cannot be fully exploited. The use of high-quality, cost-intensive roller bearing steel is necessary for the entire mass balance shaft. The usual manufacturing processes for mass balance shafts are largely limited to raw forged components.

The object of the present invention is to present a mass balance shaft on which the bearing rings can be arranged in a particularly simple and cost-effective manner, with the maximum potential for mass savings being exhausted at the same time.

This object is achieved by the features in claim 1 in terms of the method and by the features in claim 2 in terms of hardware.

• - Überschieben des Lagerrings über den Endabschnitt bis zu dem Lagerabschnitt und
• - Lagefixieren des Lagerrings in dem Lagerabschnitt,

wobei eine Lagefixierung des Lagerringes durch ein vorgespanntes elastisches Element zwischen dem Lagerring und dem Massenausgleichsgewicht erfolgt.The proposal according to the invention is to assemble the mass balance shaft from a number of components, the use of material being essentially reduced to the balance weights. Indentations (manufactured by turning and/or milling and/or grinding, etc.) are introduced into the balancing weights radially around the outside and serve to accommodate the bearing walls, which are threaded in and fixed in position. The bearing rings are fixed in position both axially and radially by the mass balance weight. So that the method steps according to the invention can be carried out, the end sections of the mass balancing weight each have a smaller outer circumference D2 up to a bearing section than the inner diameter D1 of a bearing ring. According to the invention, a mass balance shaft is produced by the following process steps:

• - Sliding the bearing ring over the end section up to the bearing section and
• - fixing the position of the bearing ring in the bearing section,

wherein the position of the bearing ring is fixed by a prestressed elastic element between the bearing ring and the mass balance weight.

In a method that does not belong to the invention, the position can be fixed by means of a pure form fit.

In addition, according to a method not belonging to the invention, the positional fixing can also be effected by soldering or by welding or by gluing.

A further reduction in mass is achieved with a mass balance shaft according to patent claim 2 in that the bearing rings extend radially outwards by at least 180° around the mass balance weight, ie. H. that the non-bearing portion of the bearing ring can be saved.

To achieve functionally required rigidity, according to patent claim 3, ribs, preferably longitudinal ribs, can also be arranged on the mass balance weight. For weight reasons, lighter materials such as aluminum, fiber composite materials (CFRP, GFRP), etc., can also be used for this purpose, as patent claim 6 describes, which offers additional weight-saving potential.

Preferably, the bearing rings according to claim 4 are made of bearing steel, such as. B. 100 Cr6.

The manufacturing method of the mass balance weight according to claim 5 is not limited to the well-known forging, but allow a wide range of manufacturing methods such as casting and sintering.

Of course, the mass balance shaft according to the invention can be provided according to claim 7 for any reciprocating internal combustion engine, it is preferably used in provided three or four-cylinder reciprocating internal combustion engines.

• - Maximale Ausnutzung des Gewichtseinsparpotenzials,
• - Es ist die Verwendung preisgünstiger, handelsüblicher Lagerringe möglich,
• - Es sind die Verwendung und der Einsatz günstigerer Werkstoffe für das Massenausgleichsgewicht möglich und dies unabhängig vom Fertigungsverfahren (Schmieden, Gießen, usw.),
• - Eine aufwendige Bearbeitung der Lagerlaufbahn auf der Ausgleichswelle kann eingespart werden (Härten, Schleifen, Finishen),
• - Es ist die Verwendung leichter Materialien zur Funktionserreichung wie z. B. von Rippen, bevorzugt Längsrippen, für die Steifigkeit möglich.

Overall, the production and design of the mass balance shaft according to the invention result in the following advantages:

• - Maximum utilization of the weight saving potential,
• - It is possible to use inexpensive, commercially available bearing rings,
• - The use and application of cheaper materials for the mass balance weight are possible, regardless of the manufacturing process (forging, casting, etc.),
• - A complex machining of the bearing raceway on the balancer shaft can be saved (hardening, grinding, finishing),
• - It is the use of light materials to achieve the function such. B. of ribs, preferably longitudinal ribs, possible for the rigidity.

• 1 zeigt eine dreidimensionale Aufsicht auf eine Massenausgleichswelle zur Verdeutlichung des Herstellverfahrens.
• 2 zeigt einen Querschnitt durch eine Massenausgleichswelle.
• 3a zeigt eine erste bevorzugte Variante.
• 3b zeigt eine zweite bevorzugte Variante.
• 4 zeigt eine Lagefixierung eines Lagerrings an einem Massenausgleichsgewicht gemäß der Erfindung.

The invention is explained in more detail below using three exemplary embodiments in five figures.

• 1 shows a three-dimensional top view of a mass balance shaft to illustrate the manufacturing process.
• 2 shows a cross section through a mass balance shaft.
• 3a shows a first preferred variant.
• 3b shows a second preferred variant.
• 4 shows a position fixation of a bearing ring on a mass balance weight according to the invention.

• - Überschieben der Lagerringe 3, 3' über die Endabschnitte 5, 5' bis zu dem Lagerabschnitt 4, 4' und
• - Lagefixieren der Lagerringe 3, 3' in den Lagerabschnitten 4, 4'.

1 shows a three-dimensional view of a mass balance shaft 1 according to the invention to illustrate the manufacturing process. The mass balance shaft 1 is provided for a reciprocating internal combustion engine, with a mass balance weight 2 with two bearing sections 4, 4', which are formed by bearing rings 3, 3' and a first inside diameter D1 (shown in 2 ) exhibit. The mass balance weight 2 has two radially circumferential, unnumbered depressions, into which the bearing rings 3, 3' can be introduced. The radially circumferential depressions form the bearing sections 4, 4' with the bearing rings 3, 3'. End sections 5, 5' of the mass balance weight 2 have a smaller outer circumference D2 (shown in Fig 2 ) than the inner diameter D1. The method for manufacturing the mass balance shaft 1 is characterized by the following method steps:

• - Sliding the bearing rings 3, 3' over the end sections 5, 5' up to the bearing section 4, 4' and
• - Fixing the bearing rings 3, 3' in position in the bearing sections 4, 4'.

The bearing rings 3, 3' are shown in large before joining, the joining process is represented symbolically in each case by an arrow. In the fixed position in the radially outer peripheral depressions, the bearing rings 3, 3 'are shown small and thus each form a bearing section 4, 4'.

In a variant that does not belong to the invention, the position of the bearing rings 3, 3' can be fixed by means of a pure positive fit. In a further variant not belonging to the invention, it is also possible to fix the bearing rings 3, 3' in position on the mass balance weight 2 by soldering or welding or gluing. In the present case, however, the position is fixed by a prestressed elastic element 6 (shown in 4 , between the bearing ring 3, 3' and the mass balance weight 2).

Furthermore, the mass balance weight 2 in the present exemplary embodiment has a stiffening strut 7 extending in the axial direction. The stiffening strut 7 can, for example, consist of a light metal or a fiber composite material such as CFRP (carbon fiber reinforced plastic) or GRP (glass fiber reinforced plastic).

Both a roller bearing and a plain bearing can be provided as the bearing for the mass balance shaft.

The bearing rings 3, 3' are preferably made of bearing steel. Next, the mass balance weight 2 can be produced by casting or sintering or forging.

2 shows a section through the mass balance shaft 2 according to the invention in the area of a bearing section 4, 4'. A stiffening strut 7 and a bearing ring 3 are arranged on the mass balance weight 2 . An inner diameter of the bearing ring is numbered with D1, the end sections 5, 5' of the mass balance weight 2 up to the bearing sections 4, 4' have a smaller outer circumference D2 compared to the inner diameter D1.

In addition, an enveloping circle is shown in dashed lines. The enveloping circle describes the space that the mass balance shaft 1 rotates needed. There is optimal utilization of the mass balance weight when the area over which the bearing ring is pushed has the contour of the enveloping circle in the area of the imbalance mass. The enveloping circle is the maximum possible diameter for joining the mass balance shaft to the outside diameter of the bearings.

3a shows a three-dimensional view of a mass balance shaft 1 according to the invention for a first preferred embodiment. In this exemplary embodiment, the bearing rings 3, 3' do not extend by 360° around the mass balance weight 2, but by approximately 270° and are again reduced in weight, ie there is no unneeded material in areas of the bearing ring 3, 3' that are not under load.

The opposite shows 3b the same mass balance weight 2 as 3a , but with bearing rings 3, 3', which extend 360° around the mass balance weight 2.

4 shows a particularly preferred way of fixing the position of the bearing rings 3, 3' on the mass balance weight 2 by means of a prestressed, elastic element 6. A three-dimensional top view of the mass balance shaft 1 according to the invention with two positionally fixed bearing rings 3, 3' is shown in each case by a prestressed elastic element 6.

The elastic element 6 is also shown enlarged in three dimensions as a separate component on the right above the mass balance shaft 1 . A section through a location 4, 4' of the mass balance shaft 1 is shown below the mass balance shaft 1. This sectional view shows how the elastic element 6 is supported on the stiffening strut 7 and fixes the bearing ring 3 in position on the mass balance weight 2 under pretension.

Summary of the invention:

The proposal according to the invention is to assemble the mass balance shaft 1 from a number of components, with the use of material being essentially reduced to the mass balance weight 2 . The bearing rings 3, 3′ are placed radially on the outside circumferentially in recesses which are threaded in according to the invention. The bearing rings 3, 3' are fixed in position axially and radially by the balancing weight 2. The bearing rings 3, 3' extend at least 180° over the circumference of the balancing weight 2.

A connection of the balancing weight 2 to the bearing rings 3, 3' is possible by positive locking, joining, soldering, welding or gluing. A special type of form fit is the connection of the bearing rings 3, 3' to the balancing weight 2 by means of a clip, represented by the elastic element 6, which holds and fixes the bearing rings 3, 3' to the balancing weight 2 in position (see Fig. 4 ).

The mass balance weight 2 can thus be made from a material that does not have to be capable of rolling bearings. This means that there is a wide range of materials that is not just limited to steel. From a functional point of view of the mass balance weight 2, it is desirable to select a material with the highest possible density.

To achieve a functionally induced rigidity, if necessary, e.g. B. also stiffening struts 7 are attached to the balance weight 2. For this purpose, lighter materials such as aluminum, CFRP, etc. can be used than those for the mass balance weight 2, which offers additional weight potential.

The manufacturing process of the mass balance weight 2 is therefore not limited to forging roller bearing steel, but allows a broad field: casting, sintering, mechanically manufactured, forming.

The bearing rings 3, 3 'are commercially available, which mainly made of bearing steel such. B. are 100Cr6.

Claims (8)

Method for producing a mass balance shaft (1) for a reciprocating internal combustion engine, with a mass balance weight (2) and at least two bearing sections (4, 4'), which are formed by bearing rings (3, 3') and have a first inner diameter D1, wherein the balancing weight (2) has recesses (4) running radially outwards, into which the bearing rings (3, 3') can be inserted, with an end section (5, 5') of the balancing weight (2) extending as far as a bearing section (4, 4' ) has a smaller outer circumference D2 than the inner diameter D1, comprising the following process steps: - sliding the bearing ring (3, 3') over the end section (5, 5') up to the bearing section (4, 4') and - fixing the bearing ring in position ( 3, 3') in the bearing section (4, 4') , characterized in that the position of the bearing ring (3, 3') is fixed by a prestressed elastic element (6) between the bearing ring (3, 3') and the mass balance weight (2 ) he follows. Mass balance shaft (1) for a reciprocating internal combustion engine, with a mass output lightweight (2) and at least two bearing sections (4, 4'), which are formed by bearing rings (3, 3') and have a first inner diameter D1, the mass balancing weight (2) having radially outwardly circumferential recesses (4) into which the bearing rings (3, 3') can be introduced, with an end section (5, 5') of the mass balance weight (2) up to a bearing section (4, 4') having a smaller outer circumference D2 than the inner diameter D1, with the bearing ring (3 , 3') is pushed over the end section (5, 5') up to the bearing section (4, 4') and the bearing ring (3, 3') is fixed in position in the bearing section (4, 4'), characterized in that the bearing ring (3, 3') is fixed in position by a pretensioned elastic element (6) between the bearing ring (3, 3') and the counterweight (2). mass balance shaft patent claim 2 , characterized in that the bearing rings (3, 3') extend to at least 180° radially outwards around the mass balance weight (2). Mass balance shaft according to one of patent claims 2 or 3 , characterized in that the mass balance weight (2) has a stiffening strut (7) in the axial direction. Mass balance shaft according to one of patent claims 2 until 4 , characterized in that the bearing rings (3, 3') are made of bearing steel. Mass balance shaft according to one of patent claims 2 until 5 , characterized in that the mass balance weight (2) can be produced by casting or sintering or forging. mass balance shaft patent claim 4 or after one of the patent claims 5 or 6 in its reference to patent claim 4 , characterized in that the stiffening strut (7) is made of a light metal or a fiber composite material. Mass balance shaft according to one of patent claims 2 until 7 , characterized in that the balancer shaft (1) is provided for a three- or four-cylinder internal combustion engine.

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