Method for manufacturing a tapered roller bearing cage and tapered roller bearing cage

Abstract

Method for manufacturing a tapered roller bearing cage (1) comprising the steps: a) Cutting out a sheet metal strip (2) from a flat sheet metal plate (3), wherein the sheet metal strip (2) corresponds to the development of a circumferential section of the base body of the tapered roller bearing cage (1); b) Rolling the sheet metal strip (2) into part of a frustoconical ring (4); c) Inserting the receiving pockets (7) for conical rollers (8) into the part of the frustoconical ring (4), d) Materially bonding of the butt joints (5, 6) of the parts of the frustoconical ring (4) to produce a closed frustoconical ring (4).

Description

[0001] The invention relates to a method for manufacturing a tapered roller bearing cage. Furthermore, the invention relates to a tapered roller bearing cage.

[0002] The manufacturing of a tapered roller bearing cage, if the cage is to be made of sheet metal, generally proceeds as follows: a cylindrical ring is first produced, which is then deformed by a forming process to assume a frustoconical shape. This involves drawing or pressing operations on the cylindrical ring to deform it accordingly.

[0003] One such solution is shown, for example, in DE 198 07 160 A1, where a tapered roller bearing cage is manufactured by press rolling a clamped sheet metal blank. Other solutions are shown in DE 103 20 323 A1, DE 602 19 986 T2, DE 10 2007 046 131 B3 and DE 31 30 610 A1.

[0004] A disadvantage of this method is that stresses are introduced into the material of the cage's base, which can have negative effects. Particularly with compressed cages, high stresses in the material are usually observed.

[0005] Furthermore, the relatively high material consumption is a disadvantage. Finally, it should be noted that the cage body exhibits uneven material thicknesses along its height due to deformation (drawing or upsetting the material). In addition, the aforementioned manufacturing process for tapered roller bearing cages is relatively complex and therefore expensive.

[0006] The invention therefore aims to propose a method for manufacturing a tapered roller bearing cage and an associated tapered roller bearing cage in which the aforementioned disadvantages do not occur. Accordingly, the economical production of a tapered roller bearing cage should be made possible, with the cage having a constant material thickness. Furthermore, it should be ensured that no stresses arise within the cage.

[0007] This problem is solved by a method comprising the steps of claim 1.

[0008] The planned steps: a) Cutting a sheet metal strip from a flat sheet metal sheet, wherein the sheet metal strip corresponds to the development of a circumferential section of the base body of the tapered roller bearing cage; b) Rolling the sheet metal strip into part of a frustoconical ring; c) Inserting the mounting pockets for tapered rollers into the part of the frustoconical ring, d) Material-bonding joining of the joints of the parts of the frustoconical ring to produce a closed frustoconical ring.

[0009] The proposed method is particularly suitable for manufacturing a segmented tapered roller bearing cage.

[0010] Preferably, a number of adjacent strips of sheet metal are cut from the sheet. This allows for very economical use of the sheet material.

[0011] The cutting of the sheet metal strips is preferably done using a laser beam.

[0012] Preferably, a sheet metal panel with a constant thickness is used.

[0013] The joints are preferably joined by welding. Laser beam welding is particularly preferred in this regard.

[0014] Alternatively, soldering can also be used for material-joining.

[0015] The mounting pockets are preferably formed by laser beam cutting. Advantageously, contact surfaces for the tapered rollers are created during the process. A particularly preferred and efficient manufacturing method involves simultaneously cutting out half of the mounting pockets with two laser beams, the two laser beams being aligned parallel to each other and equidistant from the axis of the tapered roller bearing cage.

[0016] The proposed tapered roller bearing cage consists of a sheet metal strip cut from a sheet and formed into a frustoconical ring, wherein the joints of the frustoconical ring are joined by material bonding and wherein receiving pockets for tapered rollers are provided in the frustoconical ring.

[0017] The frustoconical ring can also be composed of a number of segments. It preferably has a constant sheet thickness.

[0018] The joints of the frustoconical ring can be joined together by welding, especially by laser beam welding.

[0019] An advantage is that there is no variation in material thickness across the surface of the tapered roller bearing cage. Rather, the sheet thickness is uniform throughout. Furthermore, there is no risk of material stress, as a forming process involving drawing or pressing is not required to manufacture the cage.

[0020] The drawing shows an embodiment of the invention. It depicts: Fig. 1. Top view of a sheet of metal from which strips of metal are cut, Fig. 2 the radial section through a frustoconical ring formed from a cut-out strip of sheet metal, Fig. 3 a section of the front view of the frustoconical ring, in which two abutting butt joints were welded together, Fig. 4 the front view of the frustoconical ring into which a receiving pocket for a conical roller was incorporated, Fig. 5 the section AB according to Fig. 4 and Fig. 6 a part of the frustoconical ring in the view analogous to section AB according to Fig. 5, where the insertion of receiving pockets for conical rollers is shown using two laser beams.

[0021] In Fig. Figure 1 shows a sheet metal panel 3 with a constant thickness, from which sheet metal strips 2 are cut. The sheet metal strips 2 correspond to the development (shell development) of a frustoconical ring, which forms the base body of a tapered roller bearing cage 1 to be manufactured (see Figure 1). Fig. 4) forms. The cutting is done using a laser beam (not shown) to obtain the sheet metal strips 2 quickly and precisely. To use the material efficiently, the sheet metal strips 2 to be cut are adjacent to each other. This allows a maximum number of sheet metal strips 2 to be obtained with a small number of cuts.

[0022] The sheet metal strips 2 are bent into a frustoconical ring 4, as shown in the radial section in Fig. Figure 2 shows the frustoconical ring forming the base body of the tapered roller bearing cage to be manufactured.

[0023] When forming the ring 4 from the sheet metal strip 2, two butt joints 5 and 6 are created at a circumferential point 14. At this point, the two butt joints 5 and 6 are welded together, preferably by laser welding. The resulting weld seam is designated 13.

[0024] The receiving pockets 7 must now be inserted into the now completed base body of the tapered roller bearing cage in order to accommodate the tapered rollers 8 (see Fig. 5). In Fig. Figure 4 shows the shape of the receiving pockets 7 to be inserted. Section AB according to Fig. 4, which is in Fig. As shown in Figure 5, the lateral boundary of the receiving pocket 7 must have a contact surface 9 which is adapted to the circumferential shape of the conical roller 8.

[0025] For efficient insertion of the recording pockets 7, the following should be noted: Fig. Figure 6 indicates that the material of the frustoconical ring 4 is cut out to form the receiving pockets 7 by two laser beams 10 and 11, with each laser beam cutting out slightly more than half of the receiving pocket 7. The frustoconical ring 4 is positioned for this purpose as shown in Figure 6. Fig. 6. Two laser beam nozzles 15 are positioned on both sides of the axis 12 of the ring 4, at a defined distance a from the axis. The distance a is chosen such that, when the two laser beams 10 and 11 are parallel, a laterally limiting contact surface 9 of the receiving pocket 7 is created.

[0026] If the frustoconical ring 4 is rotated by an angle after each cutting operation, as determined by the sequence of receiving pockets 7 around the circumference of the ring 4, a 360° rotation of the ring 4 ensures that all receiving pockets 7 are cut out, with each laser beam 10, 11 cutting out only slightly more than half the outer contour of the receiving pocket 7 (for example, approximately 1 mm more cutting area than half the receiving pocket can be provided to ensure the receiving pocket is produced). Simultaneously, all starting surfaces 9 are precisely formed.

[0027] Alternatively, it is of course also possible to cut out the recording pockets 7 with a single laser beam. In this case, the entire boundary of the recording pocket must be cut out with the laser and the ring 4 must be rotated a total of 360° until all recording pockets 7 have been incorporated.

[0028] The proposed method can also be used to manufacture segmented cages. This is particularly suitable for large bearing cages, such as those required in wind turbines.

[0029] It is also possible to manufacture the cage as described in the exemplary embodiment and then cut it into segments using a laser beam. During assembly, the individual segments are welded back together. In this context, it should be noted that in this case, the material removed by the cutting process (cutting gap) must be added as a corresponding width dimension when cutting the sheet metal strips in order to achieve the exact geometry of the cage in the end.

[0030] In Fig. Point 3 leaves open the question of whether the weld seam is located in the area of ​​a receiving pocket or between two receiving pockets. Both possibilities exist.

[0031] Laser cutting and welding operations utilize laser welding and cutting robots, which are well-known examples. These typically have a swiveling and rotating worktable to position the workpiece appropriately for laser processing. Reference symbol list 1 tapered roller bearing cage 2 strips of sheet metal 3 sheet metal panels 4 frustoconical rings 5 Impact point 6 Impact point 7 Recording bag 8 Conical roller 9 Approach area 10 Laser beam 11 Laser beam 12-axis 13 weld seam 14 Scope position 15 laser beam nozzles a distance

Claims

[1] Method for manufacturing a tapered roller bearing cage (1) comprising the steps: a) Cutting out a sheet metal strip (2) from a flat sheet metal plate (3), wherein the sheet metal strip (2) corresponds to the development of a circumferential section of the base body of the tapered roller bearing cage (1); b) Rolling the sheet metal strip (2) into part of a frustoconical ring (4); c) Inserting the receiving pockets (7) for conical rollers (8) into the part of the frustoconical ring (4), d) Materially bonding of the butt joints (5, 6) of the parts of the frustoconical ring (4) to produce a closed frustoconical ring (4). [2] Method according to claim 1, characterized by , that a number of adjacent sheet metal strips (2) are cut out from the sheet metal (3). [3] Method according to claim 1 or 2, characterized by, that the cutting of the sheet metal strips (2) according to step a) of claim 1 or claim 2 is carried out by means of a laser beam. [4] Method according to any one of claims 1 to 3, characterized by , that a sheet metal panel (3) with a constant sheet thickness is used. [5] Method according to any one of claims 1 to 4, characterized by , that the material-bonded joining of the butt joints (5, 6) according to step c) of claim 1 or according to step d) of claim 2 is carried out by welding. [6] Method according to claim 5, characterized by that the welding is a laser beam welding process. [7] Method according to any one of claims 1 to 4, characterized by , that the material-bonded joining of the butt joints (5, 6) according to step c) of claim 1 or according to step d) of claim 2 is carried out by soldering. [8] Method according to any one of claims 1 to 7, characterized by, that the insertion of the receiving pockets (7) according to step d) of claim 1 or according to step c) of claim 2 is carried out by laser beam cutting. [9] Method according to claim 8, characterized by , that when inserting the receiving pockets (7) contact surfaces (9) for the conical rollers (8) are attached. [10] Method according to claim 8 or 9, characterized by , that simultaneously with two laser beams (10, 11) half of the receiving pockets (7) are cut out simultaneously, wherein the two laser beams (10, 11) are aligned parallel to each other and are spaced equally (a) far from the axis (12) of the tapered roller bearing cage (1). [11] Tapered roller bearing cage (1) manufactured according to one of claims 1 to 10, which consists of a sheet metal strip (2) cut from a sheet metal plate (3) and formed into a frustoconical ring (4), wherein the butt joints (5, 6) of the frustoconical ring (4) are joined by material bonding and wherein receiving pockets (7) for tapered rollers (8) are provided in the frustoconical ring (4). [12] Tapered roller bearing cage (1) according to claim 11, characterized by , that the frustoconical ring (4) is composed of a number of segment parts. [13] Tapered roller bearing cage according to claim 11 or 12, characterized by , that the frustoconical ring (4) has a constant sheet thickness. [14] Tapered roller bearing cage according to one of claims 11 to 13, characterized by , that the joints (5, 6) of the frustoconical ring (4) are joined together by welding, in particular by laser beam welding.

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