Bearing cage

Abstract

A bearing retainer (1) is disclosed for a rolling element bearing, the bearing retainer (1) comprising two side rings (2, 3) connected to each other by a bridge (4), wherein a cavity (5) configured to receive at least one rolling element is formed between the bridges (4), wherein at least one snap-on surface (6) is formed on the bridges (4), and wherein the cavity (5) and the snap-on surface (6) are stamped.

Description

Technical Field

[0001] The present invention relates to a bearing cage for a rolling element bearing ( / rolling bearing) according to the preamble of claim 1. In addition, the present invention relates to a method according to claim 8 for producing such a bearing cage. Background Art

[0002] Bearing cages are used in rolling element bearings ( / rolling bearings) to receive ( / contain) rolling elements and guide them between inner and outer rings. In order to arrange the rolling elements in the bearing cage, the cage is usually manufactured to include a snap-in surface for snapping into the rolling elements.

[0003] Hitherto, the snap-on surfaces of such cages have been produced by a paring process. In this process, a cage blank, preferably a pot-shaped cage blank, is first produced. The cavity contour is then punched out of the blank in a manner corresponding to the desired number of cavities. In this process, material is left at the location of the bridges, on which the snap-on surfaces will be formed later. The remaining material serving as snap-on surfaces is then ground or pared off in a manner corresponding to the number of cavities. Chips are generated as a result of this ablating or paring process. These chips adhere partly due to the lubricant required for the paring process and are therefore difficult to remove. In addition, chips that fall in an uncontrolled manner can hinder the function of the chip-cutting tool or damage the bearing during operation. Summary of the invention

[0004] It is therefore an object of the present invention to provide a bearing cage and a method for producing a bearing cage in which chip ( / chip) formation is reduced.

[0005] This object is achieved by a bearing cage according to claim 1 and a method for producing a bearing cage according to claim 8 .

[0006] The proposed bearing cage for a rolling element bearing comprises two side rings connected to each other by a bridge, wherein a cavity is formed between the bridges, in each cavity a rolling element can be received. At least one snap surface is formed on the bridge. The snap surface serves to fix the rolling element after the rolling element has been introduced into the cavity. Here, during the introduction of the rolling element into the cavity, the rolling element snaps into the snap surface.

[0007] In order not to generate any chips ( / debris) due to the cutting (paring) process or chip-forming process ( / cutting forming process) (chip-forming process), in the bearing cage proposed here, the cavity or the snap-on surface are punched. In the cages known so far, the cavity is specifically punched, but the remaining material on the snap-on surface is subsequently cut by machining. The disadvantage of this machining cutting is that lubrication must be provided during the process and it is difficult to remove the chips from the punching tool and from the cage. Since both the cavity and the snap-on surface are punched in the bearing cage proposed here, no machining cutting method is required, as a result of which no chips ( / debris) are generated.

[0008] According to one embodiment, the cavity is stamped from the radial inside to the radial outside, and the at least one snap-in surface is stamped from the radial outside to the radial inside. In this case, in particular, the at least one rolling element can be snapped into the cavity from the radial outside. As another alternative, the cavity can be stamped from the radial outside to the radial inside, wherein in this case the at least one snap-in surface is stamped from the radial inside to the radial outside. The at least one rolling element can then be snapped into the cavity from the radial inside. Thus, the cavity and the snap-in surface are always stamped in different directions.

[0009] In this way, the punched or ruptured surfaces produced during the punching of the snap-on surface are removed again by punching the cavity. This is the case on the one hand because the snap-on surface and the cavity are punched from two different directions. On the other hand, this is achieved because the cavity is punched out after the surface is punched. In this way, the snap-on surface in contact with the rolling element is machined particularly precisely without punched or ruptured surfaces.

[0010] If the cells are punched from the outside to the inside, this provides the advantage that in this case the shear zone is outwards on the metal sheet, i.e. where the punch penetrates the metal sheet. The snap surface of the rolling element thus abuts the shear zone and thereby allows the snap dimensions to be reliably maintained.

[0011] According to another embodiment, the bearing cage is manufactured from a pot-shaped bearing cage blank. The pot-shaped bearing cage blank already provides the basic shape required for the bearing cage. In addition, the cavities and snap-in surfaces can be stamped out of this bearing cage blank in a simple manner.

[0012] At least one undercut can be provided on the buckle surface. Due to this undercut, it is possible to prevent overlap with the already punched buckle surface during the punching out of the cavity. Here, preferably, the undercut is provided on both sides of each buckle surface.

[0013] According to another embodiment, the snap-fit ​​surface is stamped in a direction perpendicular to the axis of the bearing cage or in a direction angled relative to the axis of the bearing cage. Depending on the desired shape of the snap-fit ​​surface, a perpendicular orientation or an angled orientation may be selected.

[0014] Compared to chip cutting, stamped parts can be removed as waste in a simple manner. In addition, compared to previous cutting or chip cutting processes, only reduced lubrication is required. In addition, compared to previous machining cutting, stamping reduces tool wear because the punch for the snap-on surface has less stress ( / pressure) than the punch required for cutting. In addition, the manufacturing of the bearing cage is faster than with the currently used manufacturing methods using machining cutting.

[0015] According to another aspect, a method for manufacturing a bearing cage as described above is provided. The method comprises at least the following consecutive steps:

[0016] 1. Provide a pot-shaped bearing cage blank made of metal sheet;

[0017] 2. Punching out at least one buckle surface;

[0018] 3. Punch out the cavities belonging to the punched buckle surface.

[0019] Due to the fact that both the snap-fit ​​surface and the cavity are stamped out, machining cuts to the snap-fit ​​surface can be avoided. Therefore, there are no chips generated during the manufacture of the bearing cage that could damage the bearing.

[0020] In particular, in step 2, all snap surfaces are punched, and after stamping out the snap surfaces, all cavities are stamped out. For this purpose, a punch that simultaneously punches out more than one snap surface and more than one cavity can also be used.

[0021] According to another embodiment, the cavity is punched out in a direction opposite to the punching direction of the snap-in surface, and the snap-in surface is punched out in a punching direction corresponding to the direction in which the rolling element is snapped in. According to this configuration, the rolling element can be snapped in from the radial inside to the radial outside or from the radial outside to the radial inside.

[0022] In particular, the rolling elements may be spherical roller bearing rollers. However, any other type of rolling elements may also be used in such a bearing cage.

[0023] Further advantages and advantageous embodiments are indicated in the description, the drawings and the claims. In this context, in particular, the combinations of features indicated in the description and the drawings are only exemplary, so that the features may also exist alone or in other combinations.

[0024] Hereinafter, the present invention will be described in more detail using the exemplary embodiments depicted in the accompanying drawings. Herein, the exemplary embodiments and the combinations shown in the exemplary embodiments are merely exemplary and are not intended to limit the scope of the present invention. The scope is limited only by the pending claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 shows a perspective view of a bearing cage;

[0026] Figure 2 shows a plan view of a bearing cage blank including a punching tool for punching out a snap-fit ​​surface;

[0027] Figure 3 Shows Figure 2 A three-dimensional view of a bearing cage blank including two stamped snap-fit ​​surfaces;

[0028] Figure 4 Shows Figure 3 A magnified view of the stamped buckle surface on the middle left;

[0029] Figure 5 Shows Figure 3 A magnified view of the stamped buckle surface on the middle right;

[0030] Figure 6 Shows Figure 2 A three-dimensional view of a bearing retainer blank including a plurality of stamped snap-fit ​​surfaces;

[0031] Figure 7 Shows Figure 6 A plan view of a bearing cage blank including a punching tool for punching out a cavity;

[0032] Figure 8 Shows Figure 7 A detailed view of the bearing cage cavity including the bridge and the stamped snap-in surface;

[0033] Fig. 9 Shows Figure 8 a three-dimensional image of the cavity; and

[0034] Fig.10 Shows Figure 8and Fig. 9 Side view of the bridge of the cavity.

[0035] In the following, identical or functionally equivalent elements are indicated by the same reference numerals.

[0036] Reference numerals list

[0037] 1 Bearing cage

[0038] 2, 3 side ring

[0039] 4 Bridge

[0040] 5 Cavity

[0041] 6 snap surface

[0042] 8 Punch

[0043] 9 Punch die

[0044] 10 Punch

[0045] 11 Punch die

[0046] 12 Shear zone

[0047] 14 Undercut DETAILED DESCRIPTION

[0048] Figure 1 A bearing cage 1 for rolling-element bearings is shown. The bearing cage 1 comprises two side rings 2, 3 connected to each other by a bridge 4. Pockets 5 are formed between the bridges 4 and are configured to receive at least one rolling element. At least one snap surface 6 is formed on each of the bridges 4, into which a rolling element can snap.

[0049] In the bearing cages used so far, the cells 5 are stamped out and the snap-fit ​​surfaces 6 are formed by a machining paring process. Here, the material on the bridge 4 is removed to form the snap-fit ​​surfaces 6.

[0050] Chips are generated as a result of such machining cutting processes. Due to the lubricants required for the chip forming process, these chips may adhere and thus may be difficult to remove. In addition, chips that fall in an uncontrolled manner may hinder the function of the chip cutting tool. If the chips remain on the bearing cage, they may damage the rolling element bearing in operation.

[0051] In order to avoid these disadvantages, in the bearing cage 1 proposed here, it is provided that both the cavity 5 and the snap-on surface 6 are stamped out. Figures 2 to 10 This manufacturing process is described in more detail.

[0052] Figure 2 The bearing cage 1 is shown in its raw state as a pot-shaped metal sheet. In order to punch out the snap-on surface 6 in a first step, a punching tool consisting of a punch 8 and a punch die 9 is used. Figure 2 As shown in FIG. 1 , the stamping tool may include two punches 8 and two stamping dies 9 to stamp out two snap-in surfaces at the same time. Here, the snap-in surface 6 is stamped out from the radial inside to the radial outside. Thus, the rolling element can also be inserted into the finished ( / final) bearing cage 1 from the radial inside.

[0053] like Figure 3 As shown in FIG. 1 , after a first step of the punching process, the bearing cage 1 comprises two punched-out snap surfaces 6 - 1 and 6 - 2 . Figure 4 and Figure 5 A possible shape of the two snap-fit ​​surfaces 6-1 and 6-2 is shown in FIG. Figure 4 The left side and Figure 5 The right sides of the diagram represent the actual buckle surfaces.

[0054] Repeat the stamping process until Figure 6 As shown, the bearing cage 1 comprises a plurality of stamped snap-in surfaces 6 (to) distributed in the circumferential direction.

[0055] After the snap-on surface is punched out, in the next step, a cavity 5 is punched out of the bearing cage 1. The cavity 5 overlaps with the punched snap-on surface 6. Figure 6 , wherein the cavity 5 is shown by a dotted line.

[0056] As another option, the two snap-fit ​​surfaces 6 and subsequently the cells 5 overlapping these snap-fit ​​surfaces can be always stamped out. This is then repeated for each cell 5.

[0057] When the snap-fit ​​surface 6 has been punched out from the radial inside to the radial outside, the cavity 5 is punched out from the radial outside to the radial inside. Figure 7 Shown in.

[0058] If the cells 5 are punched from the radial outside to the radial inside, this has the advantage that the shear region 12 produced by the punching is outside the sheet metal surface of the bearing cage 1, i.e. where the punch 10 penetrates into the sheet metal. The snap surface 6 of the rolling element thus abuts against the shear region 12 and thereby allows the snap dimension to be reliably maintained.

[0059] Since the snap-on surface 6 and the cell 5 are punched from different sides, the punched surface or rupture surface produced during the punching of the snap-on surface 6 is removed again by punching the cell 5 .

[0060] As another option, if the snap-fit ​​surface 6 is punched from the radial outside to the radial inside, the cells 5 are punched from the radial inside to the radial outside.

[0061] Similar to punching out the snap-fit ​​surface 6, a punching tool consisting of a punch 10 for punching out the cavity 5 and a punch die ( / punching die / punch bottom die) 11 is used to punch out the cavity 5. After punching out the cavity 5, a bridge 4 is included between the two side rings 2 and 3 of the bearing cage 1, which is formed by punching out the snap-fit ​​surface 6 and then punching out the cavity 5. This is Figure 8 and Fig. 9 Shown in.

[0062] During the punching out of the snap-fit ​​surface 6, a small undercut may be applied to the punch 9. This will result in an undercut 14, which is Fig.10 As shown in . The undercut 14 can prevent the overlap with the already punched snap-on surface 6 during the punching out of the cavity 5. In this way, the dimensional accuracy of the snap-on surface 6 can be improved.

[0063] Since the bearing cage proposed here is made by stamping out both the cavities and the snap-on surfaces, the bearing cage can be produced without cuttings ( / chips). On the one hand, the manufacture of the bearing cage is faster than machining methods, and on the other hand, damage to the rolling element bearing due to cuttings of the bearing cage is reduced.

Claims

1. A bearing cage (1) for a rolling element bearing, the bearing cage (1) comprising two side rings (2, 3) connected to each other by a bridge (4), wherein: A cavity (5) configured to receive at least one rolling element is formed between the bridges (4), wherein at least one snap-in surface (6) is formed on the bridge (4), characterized in that the cavity (5) and the snap-in surface (6) are punched through.

2. The bearing retainer according to claim 1, characterized in that: The cavity (5) is punched from the radial inside to the radial outside, the at least one snap-on surface (6) is punched from the radial outside to the radial inside, and the at least one rolling element can be snapped into the cavity (5) from the radial outside.

3. The bearing retainer according to claim 1, characterized in that: The cavity (5) is punched from the radial outside to the radial inside, the at least one snap-on surface (6) is punched from the radial inside to the radial outside, and the at least one rolling element can be snapped into the cavity (5) from the radial inside.

4. The bearing cage according to any one of the preceding claims, characterized in that The bearing retainer (1) is manufactured from a pot-shaped bearing retainer blank.

5. The bearing retainer according to any one of claims 1 to 3, characterized in that: At least one undercut (14) is provided on the snap-fit ​​surface (6).

6. The bearing retainer according to any one of claims 1 to 3, characterized in that: Undercuts (14) are provided on both sides of each snap-fit ​​surface (6).

7. The bearing retainer according to any one of claims 1 to 3, characterized in that: The snap-fit ​​surface (6) is punched in a direction perpendicular to the axis of the bearing retainer or in a direction inclined relative to the axis of the bearing retainer.

8. A method for manufacturing a bearing cage (1) according to any one of the preceding claims, the method comprising at least the following consecutive steps:

1. Provide a pot-shaped bearing cage blank made of metal sheet; 2. Punching out at least one snap-fit ​​surface (6); 3. Punch out the cavities (5) belonging to the punched out snap-on surface (6).

9. The method according to claim 8, characterized in that In step 2, all the snap-fit ​​surfaces (6) are punched out, and after the snap-fit ​​surfaces (6) are punched out, all the cavities (5) are punched out.

10. The method according to claim 8 or 9, characterized in that: The cavity (5) is punched out in a direction opposite to the punching direction of the buckle surface (6), and the buckle surface (6) is punched out in a punching direction corresponding to the buckling direction of the rolling element.

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