DE102010022321A1 - Balancing shaft for compensating mass forces and mass moments of internal combustion engine, has support shaft, where unbalance mass is axially fixed and torsionally threaded on support shaft to form unbalanced section - Google Patents

Abstract

The balancing shaft (1,1') has a support shaft, where an unbalance mass is axially fixed and torsionally threaded on the support shaft to form an unbalanced section (4,5,6,7) with respect to a center of mass eccentric to a shaft axis (8). The unbalance sections are formed by multiple plate-shaped unbalanced masses lying together with the axial front surface.

Description

The invention relates to a balance shaft to compensate for inertial forces and / or moments of inertia of an internal combustion engine, with a carrier shaft and a non-rotatably threaded on the support shaft and axially fixed unbalanced mass to form an unbalanced portion with the shaft axis eccentric center of mass.

Background of the invention

Such a balancing shaft, in which the carrier shaft and the imbalance mass are produced as individual parts and then assembled, is derived from the generic type JP 2000186746 A out. The assembly is carried out by rotationally threading, ie axial pushing the unbalanced mass on the support shaft with radial fixation and positively predetermined angular alignment of the imbalance mass on the circumference of the carrier shaft. The positive rotation is generated by the non-rotationally symmetrical and partially complementary cross-sectional profiles or contours of the carrier shaft and the imbalance mass.

Object of the invention

The present invention has for its object to design a built balancer shaft of the type mentioned constructively so that the balancer shaft can be produced according to a flexible modular principle in the application specific individually sized balancer shafts have the highest possible number of identical parts.

Summary of the invention

The solution of this problem arises from the characterizing features of claim 1, while advantageous developments and refinements of the invention are the dependent claims can be removed. Accordingly, the unbalance portion of a plurality of plate-shaped, with their Axialstirnflächen contiguous imbalance masses should be formed. The modular thus constructed, d. H. consisting of several parts unbalance section is the basis for a highly flexible production of application-specific balance shafts, which are dimensioned differently with respect to their imbalance in a variety of identical parts.

For example, it is possible to make the plate-shaped imbalance masses as mutually identical sheet metal stamped parts and to vary the respectively required unbalance by the number of sheet metal stampings. Alternatively, it may also be provided that the sheet-metal stamped parts differ in their material thickness (for example in the range of 1 to 3 mm) and / or in the size of their axial end face. The number of different strengths or sizes depends on the required bandwidth and accuracy of the unbalance to be generated, with the smallest possible number, for example, 3 to 5 sizes, for reasons of technical simplification seems appropriate. The stamped sheet metal parts, which are provided with respect to the rotationally fixed Auffädeln with a non-circular support shaft contour at least partially complementary mating contour can be threaded individually or as a preassembled unit on the support shaft. Such a structural unit can be produced, for example, by means of stamped packetizing.

Furthermore, the balance shaft should have one or more bearing journal associated with the bearing journal for the radial bearing of the balance shaft in the internal combustion engine. The bearing journals are each formed by a on the support shaft also rotationally threaded and axially fixed bearing journal web and the bearing journal web firmly enclosing bearing ring. In this case, can be used as a carrier wave an application-specific cut, for example extruded profile bar with axially invariable cross-sectional profile on which both the imbalance masses and the journal pins are threaded and axially secured by suitable means.

The axial attachment of the imbalance masses and the bearing journal webs on the support shaft can be done by cap-like end pieces which are fixedly connected to the end portions of the support shaft and with their mutually facing end faces, the unbalanced masses and the bearing journal webs axially braced against each other. The attachment of the end pieces, for example, by casting, forging, sintering, or extrusion to the support shaft can be done with known types of attachment such as pressing, shrinking, screwing, pinning, riveting, gluing or welding. Conveniently, one of the end pieces serves as a receptacle for a drive wheel of the balance shaft. Alternatively, the unbalanced masses and the bearing journal webs can also be clamped axially against one another by means of end-side caulking of the carrier shaft or can also be welded to the carrier shaft.

The journal (s) may themselves be involved in the imbalance generation, in that the journal spigot extends only within a partial circumference of the bearing ring pointing in an unbalance direction. Since the bearing ring is supported in this case only in unbalance direction of the bearing journal web, it is particularly useful to weld the bearing ring with the bearing journal web.

Alternatively, a bearing journal fully supporting the bearing journal web may be provided. This then has a corresponding circular cross-section and as an option a circumferentially variable, unbalance in the largest width corresponding to the circumferentially variable bearing ring load.

In the event that the radial bearing of the balance shaft is designed as a rolling bearing and the bearing ring serves as an inner ring of the bearing, come as bearing ring material grades C16, 16MnCr5, C45, Cf53, C80 and 100Cr6 into consideration.

In principle, it is also possible to dispense with the separate bearing ring and to replace the bearing journal web by a likewise rotationally fixed on the support shaft threaded, one-piece bearing journals. Its material depends in particular on whether the radial bearing is a sliding or rolling bearing. In the case of roller bearings, the bearing journal may have a circumferentially variable width, which is minimal in the highly loaded area by the unbalance maximum and in the low or no load, opposite area. Under the minimum width is also an interruption of the bearing seat in this peripheral area to understand.

In addition, the carrier shaft should have a cross-sectional profile, the centroid of which is eccentric with respect to the shaft axis in unbalance direction. Thus, the non-circular carrier shaft, which is non-circular with regard to the positive rotation lock of the unbalanced masses, also contributes to the imbalance of the balancing shaft. Among a variety of possible cross-sectional profiles, a substantially T-shaped profile with sufficiently high rigidity against operational deflection of the balance shaft offers.

If possible and expedient, the aforementioned features and embodiments of the invention should also be combined with each other as desired.

Brief description of the drawings

Further features of the invention will become apparent from the following description and from the drawings, in which embodiments of the invention are shown. Unless otherwise stated, the same or functionally identical features or components are provided with the same reference numbers. Show it:

1 a balance shaft according to the invention in longitudinal view;

2 the balance shaft according to 1 in longitudinal section with a first bearing journal variant;

3 the balance shaft according to 1 in longitudinal section with a second bearing journal variant;

4 the section AA according to 1 with view on the first bearing journal variant according to 2 ;

5 the section AA according to 1 with view of the second trunnion variant according to 3 and

6 a sheet metal stamping to form an imbalance section in plan view.

Detailed description of the drawings

In the figures are balance shafts 1 and 1' shown to compensate for free mass forces of the second order of an internal combustion engine in four-cylinder in-line construction. In this known as Lancaster compensation balancing two balance shafts rotate with double crankshaft speed in opposite directions. The balancing shafts composed of individual components 1 . 1' each comprise a carrier wave 2 . 2 ' , two journals 3 . 3 ' and adjacent unbalance sections on both sides 4 . 5 . 6 . 7 with eccentric to the shaft axis 8th running center of mass. As from the sectional views according to the 4 and 5 Obviously, the carrier waves have 2 . 2 ' in each case a deviating from the circular cross-sectional profile, which in both cases substantially T-shaped and over the entire axial extent of the carrier shaft 2 . 2 ' is constant.

The imbalance sections 4 to 7 are each formed from a variety of plate-shaped imbalance masses in the form of sheet metal stampings, with the T-shape of the carrier shaft 2 . 2 ' complementary recesses are provided. 6 shows one of the generally with 9 designated sheet metal stampings with the recess 10 , As it is in 1 in conjunction with the 4 and 5 can be seen, have the sheet metal stampings 9 with the same thickness - here 3 mm - different sized and in the direction of the bearing pin increasing Axialstirnflächen 11 on.

The T-shaped carrier shaft contour and the mating contour of the recesses 10 effect at axial displacement a positive rotation of the on the carrier shaft 2 . 2 ' threaded sheet metal stamped parts 9 , The assembly process of stamped sheet metal parts 9 takes place such that these with the cross-sectional profile of the carrier shaft 2 . 2 ' aligned recess 10 successively on the carrier shaft 2 . 2 ' be threaded and pushed to its axial end position. From the 4 to 6 it becomes clear that the sheet metal stampings 9 and the carrier wave 2 . 2 ' generate a rectified imbalance, as well as the centroid of the carrier wave profile with respect to the shaft axis 8th is eccentric in unbalance direction.

The journals 3 . 3 ' for the radial bearing of the balance shaft 1 . 1' in the internal combustion engine are also with the carrier shaft 2 . 2 ' joined and each include a journal pin 12 . 12 ' , on both sides arranged to trunnion spacers 13 and one the journal spigot 12 . 12 ' firmly enclosing bearing ring 14 , This consists of roller bearing material and serves as an inner race for a radial needle bearing (not shown). At the journals 12 according to 2 it is circular discs with a to the T-profile of the carrier shaft 2 complementary recess (see also 4 ). The journal pins 12 ' according to 3 are shaped like the one in 6 illustrated sheet metal stamping 9 and thus support the bearing rings 14 not fully, as with the balance shaft 1 the case is, but only on a running in unbalance direction circular arc. While the bearing rings 14 on the journals 12 are pressed, the attachment of the bearing rings takes place 14 on the journals 12 ' by means of a welded joint.

The journal pins 12 . 12 ' , the journal spacers 13 and more spacers 15 and 16 on the one hand, the inner imbalance sections 5 . 6 and on the other hand, the outer imbalance section 7 and the drive-side end portion 17 the carrier wave 2 . 2 ' Separate from each other, are the same procedure as the sheet metal stampings 9 on the carrier shaft 2 . 2 ' pushed. Accordingly, the journal spacers are also 13 and the other spacers 15 . 16 with one to the carrier shaft 2 . 2 ' Provided complementary counter contour for rotational threading and formed in this case as extruded profile pieces. The axial attachment of the on the carrier shaft 2 . 2 ' aufgefädelten components finally done by means of cap-like end pieces 18 . 19 at the end sections 17 and 20 the carrier wave 2 . 2 ' be attached and the with their facing faces 21 the sheet metal stampings 9 , the journal spacers 13 , the journal journals 12 . 12 ' and the other spacers 15 . 16 each axially brace against each other at their Axialstirnflächen. The drive end piece 18 that with a tang 22 is provided for receiving a chain or gear for the shaft drive, not shown, and the opposite end piece 19 are with a to the T-profile of the respective carrier wave 2 . 2 ' complementary recess provided and with the end portions 17 . 20 the carrier wave 2 . 2 ' screwed (not shown).

LIST OF REFERENCE NUMBERS

1

balancer shaft

2

carrier wave

3

pivot

4

unbalanced section

5

unbalanced section

6

unbalanced section

7

unbalanced section

8th

shaft axis

9

Unbalanced mass / sheet metal stamping

10

recess

11

Axialstirnfläche

12

Journal web

13

Journal spacer

14

bearing ring

15

another spacer

16

another spacer

17

End portion of the carrier shaft

18

tail

19

tail

20

End portion of the carrier shaft

21

Face of the tail

22

spigot

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

• JP 2000186746 A [0002]

Claims (10)

Balance shaft ( 1 . 1' ) for balancing mass forces and / or mass moments of an internal combustion engine, with a carrier shaft ( 2 . 2 ' ) and one on the carrier shaft ( 2 . 2 ' ) rotationally threaded and axially fixed imbalance mass ( 9 ) for forming an imbalance section ( 4 . 5 . 6 . 7 ) with the shaft axis ( 8th ) eccentric center of mass, characterized in that the imbalance section ( 4 . 5 . 6 . 7 ) of a plurality of plate-shaped, with their Axialstirnflächen contiguous imbalance masses ( 9 ) is formed. Balance shaft ( 1 . 1' ) according to claim 1, characterized in that it is in the imbalance masses ( 9 ) is about sheet metal stampings. Balance shaft ( 1 . 1' ) according to claim 2, characterized in that the sheet-metal stamped parts ( 9 ) the same material thickness and different sized axial end faces ( 11 ) exhibit. Balance shaft ( 1 . 1' ) according to claim 1, characterized in that the balance shaft ( 1 . 1' ) one or more with the carrier wave ( 2 . 2 ' ) associated bearing journals ( 3 . 3 ' ) for the radial bearing of the balance shaft ( 1 . 1' ) in the internal combustion engine, wherein the bearing pins ( 3 . 3 ' ) each by one on the carrier shaft ( 2 . 2 ' ) rotationally threaded and axially fixed bearing journal web ( 12 . 12 ' ) and a the bearing journal web ( 12 . 12 ' ) tightly enclosing bearing ring ( 14 ) are formed. Balance shaft ( 1 . 1' ) according to claim 4, characterized in that the axial attachment of the imbalance masses ( 9 ) and the journal pins ( 12 . 12 ' ) on the carrier shaft ( 2 . 2 ' ) by means of cap-like end pieces ( 18 . 19 ), which are connected to the end sections ( 17 . 20 ) of the carrier wave ( 2 . 2 ' ) are fixedly connected and with their mutually facing end faces ( 21 ) the imbalance masses ( 9 ) and the journal pins ( 12 . 12 ' ) axially against each other. Balance shaft ( 1' ) according to claim 4, characterized in that the journal spigot ( 12 ' ) only within a pointing in unbalance direction partial circumference of the bearing ring ( 14 ). Balance shaft ( 1' ) according to claim 6, characterized in that the bearing ring ( 14 ) with the journal spigot ( 12 ' ) is welded. Balance shaft ( 1 . 1' ) according to claim 1, characterized in that the carrier shaft ( 2 . 2 ' ) has a cross-sectional profile whose centroid with respect to the shaft axis ( 8th ) is eccentric in the unbalance direction. Balance shaft ( 1 . 1' ) according to claim 8, characterized in that the cross-sectional profile of the carrier shaft ( 2 . 2 ' ) is substantially T-shaped. Balance shaft ( 1 . 1' ) according to claim 8, characterized in that the cross-sectional profile of the carrier shaft ( 2 . 2 ' ) is constant over its entire axial extent.

Images