DE102007011734B4 - Method for producing a bearing arrangement and bearing arrangement - Google Patents

Abstract

Method for producing a bearing arrangement (1) which has at least one bearing outer ring (3) arranged in a cast housing (2),
characterized in that
the method comprises the steps of:
a) heating the bearing outer ring (3) or a blank of the bearing outer ring (3 ') at least in a casting housing (2) facing region (4) to a temperature of at least 800 ° C;
b) introducing the heated bearing outer ring (3) into a casting mold (5);
c) at least partially encapsulating the bearing outer ring (3) with the material of the cast housing (2),
wherein after step a) and before step b) reshape the bearing outer ring (3) or the blank of the bearing outer ring (3 ') takes place.

Description

The Invention relates to a method for producing a bearing arrangement, the at least one arranged in a cast housing bearing outer ring having. Furthermore, the invention relates to a bearing assembly.

For the production of wheel hub assemblies, especially for motor vehicles, are mostly Forged parts used in one-piece outer housings. Known it is also the hub assembly using gray cast hubs and build corresponding bearing elements. In the preparation of wheel hubs are therefore forged either the required hub parts; Alternatively, gray cast iron hubs are installed by means of roller bearings in a cast housing.

This has significant costs if forging is envisaged becomes what results from the material and processing costs. At the solution however, using gray cast iron hubs results in considerable assembly costs required.

From the US 4,944,611 and from the DE 33 33 506 C2 It has become known to introduce a complete bearing in a mold and cast around with light metal. In this case, the lowest possible temperatures are sought, which should not damage the already complete camp. A maximum temperature of 750 ° C can be used, which is sufficient for casting with light metal, but not if gray cast iron is to be used as the housing material, as is usually the case in typical applications.

From the DE 42 07 607 C1 For example, there is known a method of inductively heating a mold-placed insert for a composite casting. In this case, parts of a reactor core provided with a coil are introduced into recesses, in which case the coil for inductive heating of the insert is connected to a power source.

The DE 17 63 204 A1 discloses a method of manufacturing electrical machines with a cast iron housing, wherein a specific gray cast alloy is proposed. In this case, a stator core is inserted and cast in a mold for a housing.

From the DE 196 49 919 A1 are made of composite cast brake members known to be used for example in vehicle brake drums, brake discs and the like.

The DE 196 44 356 C2 shows a seat valve with a molded valve seat.

Out procedural reasons it is desirable a good connection of a bearing outer ring with the housing material to accomplish.

Of the The invention is therefore based on the object, a method of the initially called type and to provide a corresponding bearing assembly, with or with the possible is, in easier and less expensive Way to create an optimal connection between bearing outer ring and housing, being a low cost Production should be ensured. Furthermore, the design option and freedom in the construction of the hub be high. In order to should exist a weight and cost-optimized option, in particular to produce the hubs of motor vehicles.

• a) Erwärmen des Lageraußenrings (oder eines Rohlings des Lageraußenrings) zumindest in einem dem Gussgehäuse zugewandten Bereich auf eine Temperatur von mindestens 800°C;
• b) Einbringen des erwärmten Lageraußenrings in eine Gießform;
• c) zumindest teilweises Umgießen des Lageraußenrings mit dem Material des Gussgehäuses, wobei nach Schritt a) und vor Schritt b) ein Umformen des Lageraußenrings oder des Rohlings des Lageraußenrings erfolgt.

The solution of this object by the invention is characterized in that the method comprises the steps of:

• a) heating the bearing outer ring (or a blank of the bearing outer ring) at least in a region facing the casting housing to a temperature of at least 800 ° C;
• b) introducing the heated bearing outer ring in a mold;
• c) at least partially encapsulating the bearing outer ring with the material of the cast housing, wherein after step a) and before step b) reshaping of the bearing outer ring or the blank of the bearing outer ring takes place.

Herewith is in a very advantageous way an intimate, cohesive connection achieved between the material of the bearing outer ring and the housing.

Preferably the heating takes place of the bearing outer ring or a blank of the bearing outer ring according to the above Step a) to a temperature of at least 1000 ° C. however is preferred the heating of the bearing outer ring to a temperature of less than 1200 ° C provided. The warming of the Bearing outer ring (or a blank of the bearing outer ring) is preferably carried out by induction.

Of the Bearing outer ring or the blank of the same can during its heating according to the above step a) to his Rotate the rotation axis.

It has proven useful if the forming of the bearing outer ring or of the blank comprises an enlargement of the diameter of the bearing outer ring or of the blank at its one axial end. Furthermore, it can be provided - to support the formation of the raceways - that the forming of the bearing outer ring or of the blank Ver ring of the diameter of the bearing outer ring or of the blank between its axial ends.

The Forming can be done by rolling a part of the heated area of the bearing outer ring or of the blank.

The recast of the bearing outer ring according to the above Step c) is preferably carried out by gray cast iron.

The Inventive bearing arrangement with a cast housing, in the at least one bearing outer ring is arranged, characterized in that between at least a cast housing facing area of the bearing outer ring and the cast housing a cohesive Connection exists. This is particularly by pouring the heated Bearing outer ring with the molten one Material of the housing produced.

Of the Bearing outer ring consists mostly of 100Cr6 (bearing steel); the housing is preferably made of cast iron (GG).

By The invention proposal is an atomic compound, d. H. a tight cohesive connection at least in a contact area between bearing outer ring and housing produced; So it comes to a cohesive connection in particular between the rolling bearing material used of the bearing outer ring and the cast iron of the housing.

Around the cohesive Connection between bearing outer ring and housing to favor, especially if it is the connection of the material 100Cr6 (Bearing steel) and gray cast iron for the housing The use of a flux can be very beneficial be. When pouring the Steel with another metal, such as aluminum, can the formation of a metallic compound will be difficult. In this Trap can prove itself a thin one Apply activation layer on the part to be cast before this is poured over.

Thereby can be a metallic, atomic compound of bearing steel and material of the housing (Gray cast iron) using the appropriate properties, d. H. Use of inexpensive material (gray cast iron) if sufficient Structurally stable material of the bearing outer ring (100Cr6 or SAE1055M).

The Bearing arrangement is optimized in terms of material usage and thus relatively easy.

It there is an easy way integrate the proposed procedure into existing manufacturing processes.

It can be relatively cheap gray cast iron material for the pure support function of the housing at the required Jobs are used.

Is possible it, the process heat for the Forming the bearing outer ring to activate the steel surface in the subsequent casting process to use.

Farther it is possible the weight optimization by forming the axial end portion of the bearing outer ring to a flange of bearing material.

It is possible, too, a rolling or Rollierprozess use, the raceway contour on the Inside of the wheel hub from the outside influenced.

Especially is a roll-pressing of hot (Burning) Bearing steel instead of the usual expensive and inflexible deep drawing possible.

The Bearing arrangement according to the invention proposal integrates the respective properties of gray cast iron and bearing steel through an intensive material connection and can still be in easier Integrate way into existing production processes.

In the drawing is an embodiment of Invention shown. Show it:

1 a blank of a bearing outer ring prior to its introduction into an induction heating tool,

2 the blank inserted in the induction heating tool of the bearing outer ring at the beginning of a widening process by rolling,

3 the almost completed burnishing process of the blank in the induction heating tool,

4 the blank ejected from the induction heating tool during radial curling of a portion of the blank;

5 the bearing outer ring introduced into a part of a casting mold,

6 a composite mold during pouring of the housing material and

7 the radial section through a cohesively connected to a housing Lagerau ßenring after completion of the processing.

In 1 is a hollow cylindrical blank 3 ' a bearing outer ring of a wheel hub to see in a first process step axially into an induction heating tool 6 should be inserted. The aim is to create a cohesive bond of a bearing outer ring 3 for a double-row tapered roller bearing and a cast iron housing 2 manufacture.

The induction heating tool 6 has a number of induction coils 7 on, with which the blank 3 ' can be heated to temperatures above 1,000 ° C, but below 1,200 ° C. The induction heating tool 6 can rotate about the axis of symmetry, which in 1 indicated by the arrow.

In a second process step according to 2 is the right axial end of the blank 3 ' already heated by induction to the said temperature. While now the blank 3 ' From the left by an axial force F is applied, it is from the right of a rotating forming roller 8th contacted the right axial end of the blank 3 ' radially expands.

In a further, third process step is according to 3 the right axial end of the blank 3 ' expanded in a trumpet-like manner. The expanded area forms a flange part.

By pivoting the induction heating tool 6 around 90 ° - s. 4 - becomes the blank 3 ' from the tool 6 away. Subsequently, by applying form rollers 9 an axially central region of the outer ring 3 reshaped to the effect that the lying between the two run tracks of the double-row tapered roller bearing inner section 10 (S. 7 ). For this purpose, the form rollers 9 acted upon by a corresponding force F.

In 5 is shown a later process step, in which the no longer needed induction heating tool 6 is moved away, the now at least with regard to the preprocessed bearing outer ring 3 in a two-part mold 5 is introduced by the in 5 only the lower part can be seen. The bearing outer ring 3 is still hot, having at the surface, which later faces the housing, a temperature of about 800 ° C, preferably still about 1,000 ° C.

In 6 you can see how the mold is 5 is closed and liquid gray cast iron is poured into the mold cavity.

The resulting bearing part is in 7 shown schematically in radial section. The two rows of rolling elements with the tapered rollers 11 are indicated. You can see that the material of the case 2 , so the gray cast iron, the bearing outer ring 3 jacketed. It can not be seen that it is due to the high temperature of the bearing outer ring 3 before casting with the housing material to a cohesive, atomic, metallic connection between the material of the bearing outer ring 3 (Bearing steel 100Cr6) and the housing material (gray cast iron) has come.

The manufactured molding can be referred to as steel reinforced cast iron hub become. The material usage is optimal, d. H. the high strength steel of the Bearing outer ring is optimally shaped and supported by the surrounding housing.

In expert In this way, fluxes are added which are the optimal compound between parts 2 and 3 during the casting process.

It It should be noted that after the completion of the invention proposed Measures one Finishing can be done, namely the fine machining of Raceways for the rolling elements.

While - as explained - the idea is preferably used in wheel hubs of motor vehicles, are about that out of course any other applications of the inventive concept possible. For example be plummer block housings or wheel bearings of rail vehicles called.

1

bearing arrangement

2

cast housing

3

Bearing outer ring

3 '

blank of the bearing outer ring

4

the casing facing area of the bearing outer ring

5

mold

6

Induction heating tool

7

induction coil

8th

forming roller

9

forming roller

10

inner portion

11

Tapered roller

F

force

Claims (13)

Method for producing a bearing arrangement ( 1 ), at least one in a cast housing ( 2 ) arranged bearing outer ring ( 3 ), characterized in that the method comprises the steps of: a) heating the bearing outer ring ( 3 ) or a blank of the bearing outer ring ( 3 ' ) at least in a cast housing ( 2 ) facing area ( 4 ) to a temperature of at least 800 ° C; b) introducing the heated bearing outer ring ( 3 ) into a casting mold ( 5 ); c) at least partially encapsulating the bearing outer ring ( 3 ) with the material of the cast housing ( 2 ), wherein after step a) and before step b) reshaping the bearing outer ring ( 3 ) or the blank of the bearing outer ring ( 3 ' ) he follows. A method according to claim 1, characterized in that the heating of the bearing outer ring ( 3 ) or a blank of the bearing outer ring ( 3 ' ) to a temperature of at least 1,000 ° C. A method according to claim 2, characterized in that the heating of the bearing outer ring ( 3 ) or a blank of the bearing outer ring ( 3 ' ) to a temperature of less than 1200 ° C. Method according to one of claims 1 to 3, characterized in that the heating of the bearing outer ring ( 3 ) or a blank of the bearing outer ring ( 3 ' ) by induction. Method according to one of claims 1 to 4, characterized in that the bearing outer ring ( 3 ) or the blank of the bearing outer ring ( 3 ' ) is rotated about its axis of rotation during its heating. Method according to one of claims 1 to 5, characterized in that the forming of the bearing outer ring ( 3 ) or the blank of the La geraußenrings ( 3 ' ) an enlargement of the diameter of the bearing outer ring ( 3 ) or the blank of the bearing outer ring ( 3 ' ) at its one axial end. Method according to one of claims 1 to 6, characterized in that the forming of the bearing outer ring ( 3 ) or the blank of the bearing outer ring ( 3 ' ) reducing the diameter of the bearing outer ring ( 3 ) or the blank of the bearing outer ring ( 3 ' ) between its axial ends. Method according to one of claims 1 to 7, characterized in that the forming by rolling a part of the heated area of the bearing outer ring ( 3 ) or the blank of the bearing outer ring ( 3 ' ) he follows. Method according to one of claims 1 to 8, characterized in that the encapsulation of the bearing outer ring ( 3 ) by gray cast iron. Bearing arrangement ( 1 ) with a cast housing ( 2 ), in which at least one bearing outer ring ( 3 ), wherein the bearing arrangement is produced by the method according to one of claims 1 to 9, characterized in that between at least one of the cast housing ( 2 ) facing area ( 4 ) of the bearing outer ring ( 3 ) and the cast housing ( 2 ) a cohesive connection is present. Bearing arrangement according to claim 10, characterized in that the cohesive connection between bearing outer ring ( 2 ) and housing ( 2 ) by pouring the heated bearing outer ring ( 2 ) with the molten material of the housing ( 3 ) is made. Bearing arrangement according to one of claims 10 or 11, characterized in that the bearing outer ring ( 3 ) consists of 100Cr6 (bearing steel). Bearing arrangement according to one of claims 10 to 12, characterized in that the housing ( 2 ) consists of gray cast iron (GG).