DE102018119524B4 - Process for the formation of a system of balancer shaft and bearing or bearing ring - Google Patents

Abstract

Method for forming a system from a bearing (50) or bearing ring and a balancing shaft (1) for balancing inertial forces and / or mass moments, wherein the balancing shaft (1) - an elongated base body (2), - at least one on the base body (2) formed bearing area (10), via which the balancing shaft (1) can be mounted for rotating support about an axis of rotation (R) by means of a bearing (50) and at least one first unbalance section (11) whose center of mass is outside the axis of rotation (R) of the balancing shaft (1), wherein, viewed in a projection direction (P) running parallel to a longitudinal direction (LR) of the base body (2), an outer circumferential area (A1) assigned to the first unbalance section (11) is greater than an inner diameter (ID) of a bearing (50) or a bearing ring for the bearing area (10), the first unbalance section (11) being free of steps when viewed in the longitudinal direction (LR), with a he end face (13) of the balance shaft (1) a single first unbalance section (11) is formed and the first unbalance section (11) has an inclined and / or curved course with respect to the axis of rotation (R), characterized in that a closed bearing ring or closed bearing (50) is pulled up over one end (4) of the balance shaft (1) and is shifted over the first unbalanced section (11) to the bearing area (10).

Description

The present invention relates to a method for forming a system from a balance shaft and a bearing or bearing ring.

Balance shafts are well known from the prior art, for example from DE 10 2015 218 277 A1 . Such balancing shafts are used to balance inertial forces and / or moments of inertia that are caused in an internal combustion engine by a crankshaft as it rotates. This allows operating noises and vibrations of the internal combustion engine to be reduced. To compensate for the inertia forces, imbalance sections are specifically formed on an elongated base body which, when the balance shaft rotates, provide counter-forces which compensate for the forces emanating from the crankshaft. The balance shafts are driven synchronously with the crankshaft, for example via gear wheels or belts. Depending on the design of the internal combustion engine, one or two balance shafts are used, or the balance shaft is driven at one speed or twice the speed of the crankshaft.

From the DE 10 2016 210 480 A1 In addition, a method for producing a balance shaft is known, a bearing ring suitable for mounting the shaft being pushed over an end section of the balance shaft and up to a bearing area. The bearing ring is then fixed in the bearing area.

Such a pulling or threading makes it possible in an advantageous manner to dispense with the complex closing of an open ring or strip placed on the bearing area in order to form a closed bearing ring.

From the US 2008/0121 203 A1 , of the CN 205 423 683 U and the DE 10 2009 042 297 A1 balance shafts are known whose central unbalance section, ie the unbalance section which lies between the bearing areas, tapers towards the center.

In the DE 198 30 051 C1 balancing shafts are described which have balancing weights arranged diagonally to one another within a hollow cylinder.

The DE 10 101 15 536 A1 describes a balancing shaft in which, in order to form a circular cylindrical shape, balancing molded parts are arranged on areas opposite the balancing weights.

From the DE 10 2016 210 480 A1 a method is known in which a bearing ring is pulled over the end face of the balance shaft in order to place this bearing ring in a correspondingly provided bearing area.

The DE 600 24 738 T2 relates to a balance shaft housing and, more particularly, to a housing for accommodating balance shafts provided with counterweights to cancel a vibromotive force caused by pistons.

The DE 11 2015 005 119 T5 aims to reduce the size of a mechanical device having a plurality of rotating shafts and to reduce the man-hours involved in machining and assembly, and to reduce the amount of lubricating oil required. This mechanical device has multiple rotating shafts and is configured such that two of the multiple rotating shafts are arranged adjacent to each other on the same axis,

Starting from the state of the art, the present invention sets itself the task of improving balance shafts or systems made up of a balance shaft and bearing, in particular with regard to their manufacturing complexity.

This object is achieved by a method according to claim 1. Further advantages and features of the invention emerge from the subclaims and the description and the attached figures.

• - einen länglichen Grundkörper;
• - zumindest einen am Grundkörper ausgebildeten Lagerbereich, über den die Ausgleichswelle zur rotierenden Lagerung um eine Rotationsachse mittels eines Lagers lagerbar ist; und
• - zumindest einen ersten Unwuchtabschnitt, dessen Massenschwerpunkt außerhalb der Rotationsachse der Ausgleichswelle liegt;

wobei in einer parallel zu einer Längsrichtung des Grundkörpers verlaufenden Projektionsrichtung gesehen eine dem ersten Unwuchtabschnitt zugeordnete Außenhüllkreisausdehnung größer ist als ein Innendurchmesser eines Lagers oder eines Lagerrings für den Lagerbereich, wobei der erste Unwuchtabschnitt in Längsrichtung gesehen absatzfrei bzw. stufenlos ist.According to the invention, a method is provided for forming a system from a bearing or a bearing ring and a balancing shaft for balancing inertia forces and / or moments of inertia, in particular for balancing inertia forces and / or moments of inertia of a reciprocating internal combustion engine, comprising:

• - an elongated base body;
• - At least one bearing area formed on the base body, via which the balancing shaft can be mounted for rotating mounting around an axis of rotation by means of a bearing; and
• - At least one first unbalance section, the center of gravity of which lies outside the axis of rotation of the balance shaft;

wherein, seen in a projection direction running parallel to a longitudinal direction of the base body, an outer enveloping circle extension assigned to the first unbalanced section is greater than an inner diameter of a bearing or a bearing ring for the bearing area, the first unbalanced section being stepless or stepless as seen in the longitudinal direction.

In contrast to the prior art, it is provided that the first unbalance section is stepless or stepless. As a result, changes in direction in the radial direction that would otherwise be required on the shoulder or on the step can be avoided during threading, whereby a simple, in particular easy to automate, pushing on is possible. In other words: when the bearing or the bearing ring is displaced along the longitudinal direction, viewed in the radial direction, a change in direction is only made in the radial direction when the bearing area is reached. Preferably, when the bearing ring is pushed on along the longitudinal direction in the first unbalance section, it is only moved away from the axis of rotation in the radial direction and towards the point of rotation in the bearing area.

It is preferably provided that an outside of the first unbalance section serves as a guide surface or line that is used to push on the bearing or the bearing ring, i.e. H. the bearing ring or the bearing rests at one point on the outside and by the bearing on the outside, when the bearing ring or the bearing moves in the longitudinal direction, the bearing ring or the bearing is automatically offset radially. As a result, it is advantageously sufficient to ensure a translational movement in the longitudinal direction in the case of automation when pulling up. The step-free or stepless design is provided for the longitudinal direction. Structuring along the circumference in a plane running perpendicular to the axis of rotation / longitudinal axis is conceivable.

Furthermore, it has been found in an unexpected way that a sufficient imbalance can be set even with a substantially structure-free area between the bearing area and an end face of the balance shaft. In particular, the outer enveloping circle in the projection direction means a circle that runs through the radially outermost area or points of the first unbalance section, this extreme area not being arranged in a common sectional plane running perpendicular to the projection direction, but in two, in the longitudinal direction seen, mutually offset cutting planes. In particular, one of these sectional planes runs through the strut side of the balancing shaft and the other sectional plane forms the end of the first unbalanced section at the end of the first unbalanced section facing the bearing area. It is provided in particular that the cross-section in the individual sectional planes running perpendicular to the longitudinal direction is designed in such a way that its maximum extent is smaller than the inner diameter of the bearing ring or the bearing. This makes it possible to ensure that the bearing ring or the bearing can be pulled up as a closed ring over the first unbalanced section and shifted as far as the bearing area.

As step-free or step-free is to be understood that no edge is formed in the first unbalanced section that separates two areas within the first unbalanced section. In other words: it is provided that the first unbalance section cannot be subdivided further. In particular, there is no edge that separates two areas in the first unbalance section with outer sides inclined differently to the axis of rotation. As a result, tilting of the bearing ring or the bearing in the area of the edge can also be advantageously avoided when pulling on. To avoid such an edge, the outside of the first unbalanced section runs exclusively continuously or steadily in the longitudinal direction. The direction of projection preferably runs parallel to the longitudinal direction.

According to the invention it is provided that a single first unbalance section is formed between the bearing area and an end face of the balancing shaft. In other words: one end of the first unbalanced section encompasses the face of the balance shaft and with the other end forms the edge or the transition to the bearing area. In particular, the first unbalanced section forms a collar with the other end at the transition to the bearing area, on which the mounted bearing ring or the mounted bearing can rest or interact with a form fit. Furthermore, it is provided that a ratio of a first length of the bearing area measured in the longitudinal direction to a second length of the first unbalanced section measured in the same direction is a value between 0.1 and 0.4, preferably between 0.15 and 0.35 and particularly preferred assumes between 0.2 and 0.3.

It is preferably provided that the first unbalance section tapers towards the end face of the balance shaft, in particular tapers continuously. As a result, the bearing ring or the bearing can be threaded on comparatively easily, since it can thus be ensured that the cross section at the end face is significantly smaller than the inner diameter of the bearing or bearing ring. Accordingly, when initially aligning the bearing to the balance shaft, less consideration must be given to its positional accuracy. This simplifies the mounting of the bearing or the bearing ring. For example, there is a ratio between a smallest cross section, in particular the smallest cross section measured on the end face of the balance shaft Q1 , to a largest cross-section Q2 a value between 0.8 and 1, preferably between 0.85 and 1 and particularly preferably between 0.9 and 1.

According to the invention, it is provided that the first unbalanced section, in particular a first outer side of the first unbalanced section, has an oblique and / or curved course with respect to the axis of rotation. The curved course can be described, for example, by a curvature behavior of the outer sides or lines of intersection of the first unbalance section, seen in cross section along the longitudinal direction, running essentially parallel to one another and opposite one another (extending in the longitudinal direction). The person skilled in the art understands “essentially” to mean a deviation of up to 5% or a deviation with which a desired taper, viewed in the longitudinal direction, can be achieved. In particular, the two opposite outer sides or cutting lines are bent in the same direction and the direction of curvature does not change when viewed in the longitudinal direction. However, it is conceivable that a radius of curvature for the outside changes along the longitudinal direction. For example, the radius of curvature decreases towards the end face of the balance shaft. As a result, a curved course that flattens towards the end face is achieved. In particular, the imbalance or mass in the first imbalance section can be set in a targeted manner through the course of the course. In the case of an inclined first unbalance section, it is conceivable that the opposite outer sides or lines of intersection are inclined to the axis of rotation and / or to one another, ie do not run parallel.

In a further embodiment of the present invention, it is provided that the balance shaft has a stiffening strut in the longitudinal direction. The stiffening strut increases the stability and makes it possible in an advantageous manner to dispense at least partially with material on the balance shaft. The stiffening strut can extend over the entire length of the balancing shaft or, for example, it can be limited to the area between the bearing area and a further bearing area. The stiffening strut preferably has a constant height viewed in the longitudinal direction, or the height changes along the longitudinal direction. For example, the height of the stiffening strut in the storage area or in the first unbalance section is maximum.

It is preferably provided that a ratio between the inner diameter of the bearing ring or bearing to a maximum outer envelope circle extension, e.g. B. a maximum outer enveloping circle diameter, a value between 0.8 and 1, preferably between 0.9 and 1 and particularly preferably between 0.95 and 1 assumes. This advantageously ensures that the balance shaft can be designed in a space-saving manner in spite of the enlarged outer enveloping circle.

It is preferably provided that the balance shaft has a mounted bearing ring which is positively, non-positively and / or materially connected to the bearing area of the balance shaft. For fixing purposes, an elastic element is preferably provided that is arranged in the radial direction between the bearing ring or the bearing and with which the bearing ring is pretensioned against the balance shaft. It is also conceivable that an intermediate space between the bearing ring and the balance shaft is filled with a plastic, for example by injection or insertion.

According to the invention, it is provided that a closed bearing ring or a closed bearing is pulled over one end of the balancing shaft and is displaced over the first unbalanced section up to the bearing area.

It is preferably provided that a threading movement is carried out in an automated manner. For example, a robot or a device with which the balance shaft and the bearing ring can be moved in the longitudinal direction relative to one another is used for this purpose.

Further advantages and features emerge from the following description of preferred embodiments of the subject matter according to the invention with reference to the attached figures. Individual features of the individual embodiment can be combined with one another within the scope of the invention.

• 1: schematische Darstellung einer Ausgleichswelle gemäß einer ersten bevorzugten Ausführungsform der vorliegenden Erfindung und
• 2 schematische Darstellung einer Ausgleichswelle gemäß einer zweiten bevorzugten Ausführungsform der vorliegende Erfindung.

It shows:

• 1 : a schematic representation of a balance shaft according to a first preferred embodiment of the present invention and
• 2 schematic representation of a balance shaft according to a second preferred embodiment of the present invention.

In 1 is schematically a balance shaft 1 shown. Such balancer shafts 1 serve in particular to balance inertia forces and / or moments of inertia, in particular to balance inertia forces and / or moments of inertia of a reciprocating piston internal combustion engine, in order to reduce operating noise and vibrations and thus increase driving comfort. For this purpose, imbalance sections are targeted 11 , 12 , 15th , 21st and 22nd on the balance shaft 1 formed, preferably forged, which generate inertial forces or mass moments that counteract those of a crankshaft of the internal combustion engine.

In the example shown in 1 includes the balance shaft 1 an elongated one Base body 2 , at which a first unbalance section 11 and a second unbalance section 12 are trained. Between the first unbalance section 11 and the second unbalance section 12 is a storage area 10 intended. The storage area 10 is provided as a contact area over which the balance shaft 1 by means of a warehouse 50 , in particular a roller bearing, for example a radial bearing such as a needle bearing, rotating about an axis of rotation R. is storable. There is also a third unbalance section 21st and a fourth unbalance section 22nd provided, between which another storage area 20th is arranged. It also includes the balance shaft 1 from the 1 a central unbalance section 15th between the second unbalance section 12 and the third unbalance section 21st .

The balance shafts 1 are driven synchronously by the crankshaft, for example by gears, chains or toothed belts. In the illustrated embodiment, for example, on the other storage area 20th End facing a power transmission area (not shown here) can be provided on which, for example, a gear is mounted or on which a belt rests. For example, a gear wheel can be attached to the other storage area 20th Open the facing end and connect positively and / or positively to the power transmission area. Depending on the design of the internal combustion engine, one or two balance shafts are usually used 1 that run at single or double crankshaft speed. A stiffening strut also extends 8th along the longitudinal direction LR .

In particular, it is provided that the first unbalance section 11 in a parallel to the longitudinal direction LR of the main body 2 ongoing project direction P seen an outer enveloping circle with an outer enveloping circle extent A1 can be assigned. The outer enveloping circle is defined by the outermost regions or points of the first unbalance section, as seen in the radial direction 11 set. In particular, the extent of the outer enveloping circle is an outer enveloping circle diameter. As can be seen in the embodiment shown, the outermost regions of the first unbalance section are seen in the radial direction 11 not in a common perpendicular to the thing of rotation R. running cutting plane, but in two in the longitudinal direction LR the balance shaft 1 staggered levels. One of the said levels is preferably located on the front side 13 the balance shaft 11 , while the other plane corresponds to that end of the first unbalance section 11 is to be assigned that is directly to the storage area 10 adjoins.

The outer enveloping circle preferably has an outer enveloping circle extent A1 that is larger than an inside diameter ID of a warehouse 50 or bearing inner ring. Around the bearing ring or the bearing 50 about the end 4th the balance shaft 1 To draw, it is provided that in each of the individual cutting planes running parallel to the projection direction, a maximum extent of the first unbalance section 11 is smaller than the inside diameter ID of the camp 50 or bearing ring. This allows the bearing ring or the bearing 50 despite the greater extent of the outer enveloping circle A1 on the balance shaft 1 wind up and up to the storage area 10 move to there at the storage area 10 to be fixed.

The opposite of the inside diameter ID enlarged outer enveloping circle A1 thus forms a measure for the spatial profile of the first unbalance section 11 , namely with regard to a radial offset of the individual cutting planes with respect to the axis of rotation R. or the direction of projection P along the longitudinal direction LR or axis of rotation R. . Due to the increased offset, the desired imbalance can be set, in particular set in a targeted manner, without the possibility of the bearing or the bearing ring being pulled onto the balance shaft 1 to renounce. It is preferably the first unbalanced section 11 around the only unbalance section between the bearing area 10 and the front 13 the balance shaft 1 . Furthermore, the balance shaft 1 in the storage area 10 one perpendicular to the axis of rotation R. measured storage area extension A2 which is smaller than the inner diameter ID of the bearing ring and therefore also smaller than the extent of the outer enveloping circle A1 .

In order to achieve the desired, comparatively large, outer enveloping circle, it is preferably provided that the first unbalanced section 11 along the direction of projection P or longitudinal direction LR runs curved, ie opposite sides are curved and have the same curvature behavior or a similar curvature behavior, for example. The curvature behavior includes both the direction of curvature and a radius of curvature that corresponds to the outer course or an outer side 14th of the first unbalance section 11 can be assigned. A parabolic course of curvature is also conceivable. Furthermore, it is provided that an outside 14th of the first unbalance section 11 as a guide for the bearing ring or the bearing 50 when threading. In particular is the first unbalance section 11 designed such that the bearing ring when pushed on along the longitudinal direction LR the balance shaft 1 is only offset in a single radial direction until the bearing ring or the bearing 50 the storage area 10 has reached. This advantageously makes it possible to dispense with a complicated threading movement during assembly of the bearing ring, during which, if necessary, several changes of direction are required in the radial direction. The bearing ring is preferably located through the outside when it is guided 14th on this outside 14th of the first unbalance section 11 on. As a result, a threading movement can also be carried out in an automated manner without further ado, for example by means of a robot or robot arm. For example, in this case the robot only has to make an axial movement or movement along the longitudinal direction LR induce while the outside 14th for aligning the bearing 50 or the bearing ring.

It is preferably provided that the first unbalance section 11 step-free or step-free, in particular the outside serving as a guide for the bearing ring or the bearing 14th of the first unbalance section 11 . This avoids the need for an abrupt change of direction in the radial direction when pulling up or the bearing 50 tilted when threading. In particular, the entire area forms between the streak side 13 and a single, continuously formed first unbalance section 11 . In other words: the first unbalance section 11 cannot be split lengthways LR Subdivide successively arranged subsections.

It is also provided that a ratio of one in the longitudinal direction LR measured first length L1 of the storage area 10 to a second length measured in the same direction L2 of the first unbalance section assumes a value between 0.1 and 0.4, preferably between 0.15 and 0.35 and particularly preferably between 0.2 and 0.3. It is also conceivable that an outer circumference of the end face 13 the balance shaft in the projection direction P seen only in certain areas or not at all congruent with the outer circumference of the storage area 10 runs.

The one for the first unbalance section 11 The explanations described can also be applied to the second unbalance section 12 , the third unbalance section 21st , the fourth unbalance section 22nd and the central unbalance section 15th transfer.

In the 2 is schematically a balance shaft 1 illustrated in accordance with a second preferred embodiment of the present invention. The balance shaft 1 from the 2 differs from that from the 1 essentially only to the effect that instead of a curved course the outside 14th an oblique and / or linear course on the outside 14th of the first unbalance section 11 is provided. It is conceivable that slopes from opposite outer sides 14th of the first unbalance section 11 are different. This allows, for example, a to the front 13 the balance shaft 1 tapering, in particular continuously tapering, first unbalance section 11 realize. In particular is the first unbalance section 11 designed so that this in the longitudinal direction LR seen exclusively rejuvenated. For example, there is a ratio between a smallest cross section Q1 , especially on the front 13 the balance shaft 1 measured smallest cross-section, to a largest cross-section Q2 a value between 0.8 and 1, preferably between 0.85 and 1 and particularly preferably between 0.9 and 1. In the in 2 embodiment shown are the smallest cross section Q1 and the largest cross-section Q2 the fourth unbalance section because of the better overview 22nd drawn. However, it is clear to a person skilled in the art that the dimensions shown here apply equally to the first unbalance section 11 be valid. Furthermore, it is clear to the person skilled in the art that instead of the fourth non-alarm section 22nd a power transmission area can be provided over which the balance shaft 1 can be driven. Alternatively, the force transmission area adjoins the fourth unbalance section in the longitudinal direction 22nd on.

List of reference symbols

1

Balance shaft

2

Base body

4th

The End

8th

Stiffening strut

10

storage area

11

first unbalance section

12

second unbalance section

13th

Face

14th

Outside

15th

central unbalance section

20th

further storage area

21st

third unbalance section

22nd

fourth unbalance section

50

warehouse

A1

Outer enveloping circle extension

A2

Storage area expansion

ID

Inside diameter

P

Direction of projection

LR

Longitudinal direction

R.

Axis of rotation

Q1

smallest cross-section

Q2

largest cross-section

L1

first length

L2

second length

Claims (6)

Method for forming a system from a bearing (50) or bearing ring and a balancing shaft (1) for balancing inertial forces and / or mass moments, wherein the balancing shaft (1) - an elongated base body (2), - at least one on the base body (2) formed bearing area (10), over which the balancing shaft (1) can be mounted for rotating support around an axis of rotation (R) by means of a bearing (50) and - at least one first unbalance section (11), the center of gravity of which is outside the axis of rotation (R) of the balancing shaft (1), wherein, viewed in a projection direction (P) running parallel to a longitudinal direction (LR) of the base body (2), an outer circumferential area (A1) assigned to the first unbalance section (11) is greater than an inner diameter (ID) of a bearing (50) or a bearing ring for the bearing area (10), the first unbalanced section (11) being free of steps when viewed in the longitudinal direction (LR), with between the bearing area (10) and a single first unbalance section (11) is formed on an end face (13) of the balancing shaft (1) and the first unbalance section (11) has an inclined and / or curved course with respect to the axis of rotation (R), characterized in that a closed bearing ring or closed bearing (50) is pulled up over one end (4) of the balance shaft (1) and is shifted over the first unbalanced section (11) to the bearing area (10). Procedure according to Claim 1 , wherein the first unbalance section (11) tapers towards the end face (13) of the balance shaft (1). Method according to one of the preceding claims, wherein the balancing shaft (1) has a stiffening strut (8) in the longitudinal direction (LR). Method according to one of the preceding claims, wherein a ratio between the inner diameter (ID) of the bearing ring or bearing (50) to a maximum outer enveloping circle extension (A1) assumes a value between 0.8 and 1. Method according to one of the preceding claims, wherein the balancing shaft (1) has a mounted bearing ring which is positively, non-positively and / or materially connected to the bearing area (10) of the balancing shaft (1). Method according to one of the preceding claims, wherein a threading movement is carried out in an automated manner.

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