CN112610610A

CN112610610A - Bearing seat

Info

Publication number: CN112610610A
Application number: CN202010958647.0A
Authority: CN
Inventors: M·米罗斯拉夫; K·简; D·卡尔
Original assignee: Miba Sinter Austria GmbH
Current assignee: Miba Sinter Austria GmbH
Priority date: 2019-10-04
Filing date: 2020-09-14
Publication date: 2021-04-06
Also published as: DE102020125328A1; AT522877A4; AT522877B1

Abstract

The invention relates to a bearing block (4) for a balance shaft (2) of an internal combustion engine, comprising a main body (8) for receiving a bearing element (9), wherein the main body (8) has an outer surface (15) and a receiving region (16) for a tubular protective element (5) is formed on one axial end region of the outer surface. The receiving region (16) has at least one lateral recess (20).

Description

Bearing seat

Technical Field

The invention relates to a bearing seat for a balance shaft of an internal combustion engine, comprising a base body for receiving a bearing element, the base body having an outer surface and a receiving region for a tubular protective element being formed at one axial end region of the outer surface.

The invention also relates to a bearing seat arrangement comprising at least one bearing seat and a tubular protective element connected to the bearing seat.

The invention also relates to a balance shaft arrangement comprising a balance shaft and a bearing housing arrangement.

The invention also relates to a method for powder-metallurgical production of a bearing block for a balance shaft of an internal combustion engine, comprising a base body for receiving a bearing element, the base body having an outer surface and a receiving region for a tubular protective element being formed on one axial end region of the outer surface, comprising the following steps: filling the sintered powder into the female die; compacting the sintering powder into a bearing seat blank; sintering the bearing seat blank to form the bearing seat.

Background

Balancing shafts are known in internal combustion engines for reducing vibrations caused by free inertia forces and moments of inertia. The balancing shaft is usually driven by a crankshaft, for which purpose the crankshaft is operatively connected to the balancing shaft by means of gears or belts or chains. If the balancing shaft is arranged in the region of the sump, so-called splash losses (Planschverluste) occur.

In order to avoid splash losses, it is known from the prior art to arrange the balancing shaft at least in regions in a tube. DE 4412476 a1, for example, describes a balancing shaft which has bearing journals at one or both shaft ends for supporting the shaft, one of the bearing journals having a drive element for the balancing shaft next to the bearing point. A prefabricated pivot (Andrehungen) is provided at the shaft end, to which a sleeve which surrounds the shaft in a rotationally symmetrical manner is fixedly connected, for example pressed or glued.

DE 102014224772 a1 describes a balancing shaft for an internal combustion engine of a motor vehicle, which has at least one balancing weight, which is surrounded on the circumferential side by a closed plastic layer, which forms a body that can be rotated about an axis and is mounted rotatably in a housing on its outer circumferential side.

DE 102013207800 a1 also describes a balancing shaft with a tube whose circumference encloses the balancing weight in a form-fitting manner to the outer shape thereof.

Disclosure of Invention

The aim of the invention is to simplify the splash protection arrangement for a balancing shaft.

In the bearing block mentioned at the beginning, the object is achieved as follows: the receiving region has at least one undercut (Hinterschneidung).

The object of the invention is also achieved by the bearing seat arrangement mentioned at the outset, which has a bearing seat according to the invention.

The invention is further solved by the balance shaft arrangement according to the invention by a bearing block arrangement according to the invention.

The object of the invention is also achieved by the initially mentioned method, according to which at least one projection projecting in the axial direction and/or in the radial direction from the receiving region is formed in order to form at least one undercut in the receiving region on the blank, and at least in the embodiment variant in which the projection projects only in the axial direction from the receiving region, the projection is pressed in the axial direction at least to such an extent that it projects in the radial direction from the receiving region.

It is advantageous here that the tubular protective element can be prevented from sliding axially more simply by the at least one undercut. There is no need to bond or press-fit protective elements as is known in such bearing seat arrangement assemblies in the prior art. However, the protective element can also be removed again simply.

According to one embodiment of the invention, it can be provided that a plurality of lateral recesses are provided distributed in the circumferential direction, which extend only over a partial region of the circumference of the receiving region. The sheathing of the tubular protective element can be further simplified in this embodiment variant, in particular if it is made of plastic, since no overlapping partial regions can be formed on the circumference of the receiving region. It has nevertheless been determined that the holding strength of the protective element is not (significantly) adversely affected.

Alternatively or additionally, according to a further embodiment of the invention, a plurality of lateral recesses can also be provided in the axial direction. On the one hand, the holding strength of the protective element on the bearing seat can thereby be increased. On the other hand, this also allows the bearing block arrangement to be better adapted to the axial length of the balance shaft. Furthermore, axial sliding of the protective element can also be prevented better by the side recesses arranged one behind the other in the axial direction.

In order to simplify the sheathing of the tubular protective element, it can be provided according to a further embodiment variant of the invention that the undercut has a height on the receiving region selected from 0.1mm to 1mm, and/or that at least one side of the undercut is designed to be inclined relative to the axial direction by an inclination angle selected from the range of 80 ° to 175 °.

According to a preferred embodiment of the invention, in order to produce the undercut more economically, it can be provided that the bearing seat is made of sintered material.

According to a further embodiment variant of the invention, the undercut can be designed in the form of a thread or a bayonet connection, as a result of which the mounting and dismounting of the tubular protective element can be simplified and a high holding strength thereof on the bearing block can be ensured.

In order to further increase the reliability against axial sliding, it can be provided according to one embodiment of the bearing seat arrangement that the protective element has a retaining element projecting radially inward in at least one end surface region. In the assembled state of the bearing block arrangement, the retaining element can act from behind on the undercut, so that a kind of "hook" can be formed between the bearing block and the protective element.

According to one embodiment of the method, it can be provided that the at least one projection is pressed after sintering (verpress). Fractures in the region of the projections can thus be better avoided. Although the bearing seat has a relatively high hardness after sintering, it has been determined that even with this embodiment, no cracks are produced in the undercut region of the bearing seat.

According to a further embodiment of the method, the bearing seat can be calibrated after sintering, and the pressing of the at least one projection takes place simultaneously with the calibration. This process can be shortened and tolerance deviations which can occur by pressing of the at least one projection in the bearing seat receiving region can be eliminated.

Drawings

For a better understanding of the present invention, reference is made to the following drawings which illustrate the invention in detail. Here, the following are shown in a simplified schematic representation:

FIG. 1 illustrates, in cross-section, a portion of a balance shaft configuration assembly;

figure 2 shows in cross-section a detail of an embodiment variant of the bearing seat arrangement;

fig. 3 shows a detail of an embodiment variant of the bearing block in a cross-sectional view;

fig. 4 shows the sintered bearing seat blank in an oblique view.

Detailed Description

It is first pointed out that in different embodiments identical components are provided with the same reference signs or the same component names, wherein the disclosure contained in the entire description can be transferred in a meaningful manner to components having the same reference signs or the same component names. Likewise, the positional references selected in the description, such as above, below, side, etc., relate to the direct description and the figures shown and are to be understood as meaning the new position when the position is changed.

Fig. 1 shows a sectional view of a part of a balance shaft arrangement 1. The balance shaft arrangement 1 comprises a balance shaft 2 (also referred to as mass balance shaft) and a bearing housing arrangement 3.

The bearing housing arrangement 3 comprises at least one bearing housing 4 and a tubular protective element 5 (also referred to as a protective sleeve) connected to the bearing housing 4. Two or more bearing blocks 4 may also be provided for supporting the balance shaft 2. In this case, all bearing blocks 4 can be constructed identically or at least functionally identical, so that the following description can be transferred to all bearing blocks 4.

The at least one bearing block 4 is preferably constructed in one piece.

As can be seen from fig. 1, the balance shaft 2 has journals 6 (only one is shown in fig. 1). The journal 6 extends through a through hole 7 in the bearing block 4. For this purpose, the bearing block 4 has a base body 8, in which the through-hole 7 is formed. The through-opening 7 serves to receive a bearing element 9 in which the journal 6 of the balancing shaft 2 is mounted. The bearing element 9 is thus arranged in the radial direction between the basic body 8 and the balance shaft 2.

The bearing element 9 may be a rolling bearing or a plain bearing. Alternatively, the bearing structure can also be formed by a coating of the inner circumferential surface of the base body 8 which circumferentially defines the through-openings 7. In this case, the bearing element 9 and the base body 8 are of one-piece design.

It can also be seen from fig. 1 that the bearing journal 6 extends through the bearing block 4, so that a transmission element 10 for transmitting a rotational movement can be provided on the part of the bearing journal 6 projecting out of the bearing block, which can be connected to the bearing journal 6 in a rotationally fixed manner, for example by means of a screw 11. The transmission element 10 may be a gear, a toothed pulley or a sprocket. The transmission element 10 is driven by the crankshaft of the internal combustion engine for rotational movement by at least one further transmission element arranged on the crankshaft, which is known per se and is therefore not further shown.

If the transmission element 10 is arranged directly adjacent to the bearing block 4, as shown in fig. 1, the bearing block 4 can also have the function of an axial bearing on the end face 12 facing the transmission element 10, for example in the form of a coating of this end face 12.

The bearing block 4 can also have a web 13 which is provided with a through-opening 14 in order to fasten the bearing block to a component of the internal combustion engine, in particular the crankcase, by means of a screw which passes through the through-opening 14.

The base body 8 of the bearing housing 4 has an outer surface 15. In an axial end region of the outer surface 15, a receiving region 16 for the tubular protective element 5 is formed. The receiving region 16 extends in the axial direction 18 over a partial region of the surface 15, starting from an end face 17 of the bearing block 4 facing the balancing shaft 2. The partial region may be between 10% and 80%, in particular between 15% and 45%, of the length of the bearing seat in the axial direction 18. Preferably, the bearing seat 4 has an annular web 19 or shoulder on the second end region of the receiving region 16, up to which the protective element 5 can be pushed onto the bearing seat 4.

In order to better fix the protective element 5 on the bearing block 4, provision is now made for: the receiving area 16 has at least one undercut 20. For this purpose, at least one projection 21 is preferably provided or formed in the receiving region, which projection projects in the radial direction 22 from the receiving region 16.

The tubular protective element 5 can be designed to be smooth on the inside, so that a better fixation in the receiving region 16 can be achieved only by the cross-sectional widening around the receiving region 16 due to the at least one projection 21. Here, an overlap (may also be formed between the projection 21 and the protective element 5

) In which the receiving region 16 has an outer diameter by means of the projection 21, which outer diameter is greater than the inner diameter 23 of the protective element 5 in the region of the at least one projection 21.

However, according to one embodiment of the invention shown in fig. 2, it can also be provided that the protective element 5 has at least one retaining element 26 in the region of at least one end face 24, which protrudes radially inward beyond the inner surface 25 of the protective element 5. The holding element 26 can be configured, for example, as an annular strip. However, it is also possible to arrange or form a plurality of holding elements 26 distributed, in particular uniformly distributed, over the inner circumference of the protective element 5.

Furthermore, the holding element 26 can be arranged on the inner surface directly adjacent to the end face 24.

The holding element 26 can be inserted into the undercut 20, as a result of which a better fixing of the protective element 5 on the bearing block can be achieved.

The at least one projection 21 can also be arranged in the receiving region 16 of the bearing block 4 directly adjacent to the end face 17 of the bearing block 4.

The at least one projection 21 may also be configured as an annular strip. However, according to a further embodiment variant of the invention, it is also possible to provide a plurality of undercuts 20 distributed, in particular uniformly distributed, in the circumferential direction of the receiving region 16, in each case a plurality of projections 21 spaced apart from one another being arranged or formed distributed over the circumference of the receiving region 16. The projections 21 and thus also the undercuts 20 extend here only over a partial region of the circumference of the bearing block 4 in the receiving region 16. The partial region can be, for example, between 2% and 40%, in particular between 5% and 20%, of the total circumference of the receiving region 16.

In the case of multiple projections 21, a space may be formed between the projections 21 (and thus between the side recesses 20 of the finished bearing seat 4). However, the plurality of projections 21 can also be embodied without a distance. This, in turn, produces an annular strip-like design of the projections 21, but which is easier to mold into the side recesses 20.

Furthermore, in the case of a plurality of projections 21, all projections 21 may be configured identically. The projections 21 may also be configured differently. For example, the projections 21 can have different widths in the axial direction 18 and/or different lengths in the circumferential direction and/or different heights in the radial direction, so that the side recesses 20 made of the projections 21 are also configured differently. So that tolerance fluctuations can be compensated.

Furthermore, the plurality of side recesses 20 may not only be arranged alongside one another in the circumferential direction. According to a further embodiment variant of the invention, the plurality of lateral recesses may alternatively or additionally also be arranged one after the other in the axial direction 18. Accordingly, a plurality of projections 21 may also be arranged one behind the other in the axial direction 18. See the above description for the projection 21.

The side recesses arranged in succession in the axial direction 18 may be configured to coincide in succession in the axial direction 18. However, there is also the possibility that the "rows" of lateral recesses 21 are configured offset from one another in the circumferential direction.

According to an embodiment variant of the invention, it can be provided that the undercut or undercuts 20 are designed in the form of a thread or a bayonet connection, i.e. a part of a bayonet connection. The other part of the bayonet connection is formed by the holding element 26 of the tubular protective element 5.

According to a further embodiment variant of the invention, the lateral recess 20 can have a (maximum) height 27 at the receiving region 16, which is selected from the range from 0.1mm to 1mm, in particular from 0.1mm to 0.4mm, as can best be seen from fig. 3, which shows a detail of a further embodiment variant of the bearing block 4 in cross section. It should be noted from this figure that the side recesses 20 may have different side walls. For example, according to one embodiment of the invention, it can be provided that at least one side wall 28 of the undercut is inclined at an inclination angle 29 with respect to the axial direction 18, the inclination angle 29 preferably being selected from the range of 80 ° to 175 ° according to one embodiment variant with respect thereto. Fig. 3 shows an embodiment variant in which both side walls 28 are inclined. As shown in fig. 3, the side walls 28 may directly adjoin one another in the axial direction 18, so that a "parting line" (Scheide) may be formed. A transition surface 30 may be formed between the two side walls 28 as shown in phantom in fig. 3. The transition surface 30 may, for example, be inclined at different inclination angles 29 with respect to the axial direction 18. For example, the transition surface 30 may be configured parallel to the receiving area 16.

The side wall 28 may be configured to be inclined with respect to the axial direction 18 at the same inclination angle 29. The side walls 28 can also be inclined with respect to the axial direction 18 at different inclination angles 29 from one another.

The bearing housing 4 may be made of a solid material, such as cast and/or machined. According to a further embodiment of the invention, however, the bearing block is produced from a sintered material, in particular sintered steel, according to a powder metallurgy method.

Powder metallurgical processes are known per se from the relevant prior art. The method according to the invention thus comprises at least the following steps: the sintered powder is filled into a female mold, wherein preferably metal powder is used in the present invention, then the sintered powder is compacted into a bearing housing blank 31 and subsequently the bearing housing blank 31 is sintered to form the bearing housing. Fig. 4 shows an embodiment variant of the bearing seat blank 31. In particular, four projections 21 can be seen, which project in the axial direction 18 (fig. 1) over the end face 17 of the bearing seat blank 31. It should again be noted that other numbers of projections 21 than four may be constructed within the scope of the invention in accordance with the above description.

When the sintered powder is pressed to form the bearing seat blank 31, the projection 21 is also formed by extrusion by a corresponding shaping of the punch, so that subsequent machining of the bearing seat blank 31 to produce the projection 21 is not required.

Alternatively or additionally, the projection 21 can also be configured to project in the radial direction from the receiving region 16.

In order to form the undercut 20 (fig. 1 to 3), the projection or projections 21 are pressed to such an extent in the axial direction 18 (fig. 1) that the at least one projection 21 no longer projects beyond the end face 17, but rather is at least approximately planar with the end face 17. By the resulting displacement of the pressed sintering powder in the axial direction 18, the at least one undercut 20 is formed in such a way that the material also moves in the radial direction and thus protrudes in the radial direction beyond the receiving region 16.

Preferably, the at least one projection 21 is produced by powder pressing in such a way that it projects only in the axial direction 18, i.e. does not project in the radial direction beyond the receiving region 16 after powder pressing and before sintering.

The pressing, i.e. the material displacement, of the at least one projection 21 can be carried out by means of a punch, for which purpose the bearing seat blank 31 can be placed in a female mold. Although blank machining of the bearing seat blank is possible, the pressing of the at least one projection 21 is preferably carried out only after sintering, i.e. on the sintered bearing seat blank 31.

According to one embodiment variant, the pressing of the at least one projection 21 can be carried out in particular with the calibration of the sintered bearing seat blank 31. Calibration is a method step in which the geometric accuracy of the sintered bearing seat blank 31 is increased by pressing the sintered bearing seat blank 31 into a calibration die using a punch.

As shown in fig. 4, the bearing seat 4 can have at least one recess in the end face 17 for supplying lubricant by means of four grooves 32.

The examples show possible embodiment variants, wherein the individual embodiment variants can be combined with one another.

For the sake of clarity, it is finally pointed out that these are not necessarily shown to scale in order to better understand the structure of the bearing housing 4 or the bearing housing arrangement 3 or the balance shaft arrangement 1.

List of reference numerals

1 balance shaft arrangement assembly

2 balance shaft

3 bearing seat configuration subassembly

4 bearing seat

5 protective element

6 journal

7 through hole

8 base body

9 bearing element

10 drive element

11 screw

12 end face

13 contact piece

14 through hole

15 surface of

16 receiving area

17 end face

18 axial direction

19 lath

20 side concave part

21 projection

22 radial direction

23 inner diameter

24 end face

25 inner surface

26 holding element

27 height

28 side wall

29 angle of inclination

30 transition surface

31 bearing seat blank

32 grooves

Claims

1. Bearing seat (4) for a balance shaft (2) of an internal combustion engine, comprising a base body (8) for receiving a bearing element (9), wherein the base body (8) has an outer surface (15) and a receiving region (16) for a tubular protective element (5) is formed on one axial end region of the outer surface (15), characterized in that the receiving region (16) has at least one undercut (20).

2. A bearing housing (4) according to claim 1, characterized in that a plurality of side recesses (20) are provided distributed in the circumferential direction, which extend only over a partial region of the circumference of the receiving region (16).

3. A bearing housing (4) according to claim 1 or 2, characterized in that a plurality of side recesses (20) are provided in the axial direction (18).

4. A bearing housing (4) according to any of claims 1 to 3, characterized in that the side recess (20) has a height (27) on the receiving area (16) selected from 0.1 to 1 mm.

5. A bearing housing (4) according to any of claims 1 to 4, characterized in that at least one side wall (28) of the side recess (20) is configured to be inclined at an inclination angle (29) with respect to the axial direction (18).

6. A bearing housing (4) according to claim 5, characterized in that the inclination angle (29) is selected from the range of 80 ° to 175 °.

7. A bearing housing (4) according to any of claims 1 to 6, characterized in that the bearing housing is made of sintered material.

8. A bearing housing (4) according to any of claims 1 to 7, characterized in that the side recess (20) is configured in the form of a screw thread or a bayonet connection.

9. Bearing housing arrangement comprising at least one bearing housing (4) and a tubular protective element (5) connected to the bearing housing (4), characterized in that the bearing housing (4) is constructed according to one of claims 1 to 8.

10. A bearing housing arrangement (3) according to claim 9, characterized in that the protective element (5) has a retaining element (26) projecting radially inwards in the region of at least one end face (24).

11. A balance shaft arrangement (1) comprising a balance shaft (2) and a bearing housing arrangement (3), characterized in that the bearing housing arrangement (3) is constructed according to claim 9 or 10.

12. Method for powder metallurgical production of a bearing seat (4) for a balance shaft (2) of an internal combustion engine, comprising a base body (8) for receiving a bearing element (9), wherein the base body (8) has an outer surface (15) and a receiving region (16) for a tubular protective element (5) is formed on one axial end region of the outer surface (15), comprising the following steps:

-filling the sintered powder into a female mould;

-compacting the sintered powder into a bearing housing blank (31);

-sintering the bearing housing blank (31) to form a sintered bearing housing blank (31);

characterized in that, in order to form at least one undercut (20) in the receiving region (16) on the bearing seat blank (31), at least one projection (21) is formed which projects in the axial direction (18) and/or in the radial direction from the receiving region (16), and in at least one embodiment in which the projection (21) projects in the axial direction (18) only from the receiving region (16), the projection (21) is pressed in the axial direction (18) at least to such an extent that it projects in the radial direction from the receiving region (16).

13. Method according to claim 12, characterized in that the pressing of the at least one protrusion (21) is performed after sintering.

14. Method according to claim 13, characterized in that the sintered bearing housing blank (31) is calibrated after sintering and the pressing of the at least one protrusion (21) is performed simultaneously with the calibration.