METHOD FOR PRODUCING A RING WITH A TOOTHING

Abstract

A method for producing a ring with a toothing may involve (a) ring rolling a pre-ring to form a ring blank, (b) introducing a pre-toothing into the ring blank to form a pre-toothed ring, wherein the pre-toothing has teeth with a first tooth height, (c) heating, quenching, and tempering the pre-toothed ring to form a heat-treated pre-toothed ring, and (d) finish-toothing the heat-treated pre-toothed ring to form a ring with a toothing. The toothing may have teeth with a second tooth height that is greater than the first tooth height. Further, the introducing of the pre-toothing or the finish-toothing of the heat-treated pre-toothed ring may be performed by way of a metal machining process.

Claims

1.-12. (canceled)

13. A method for producing a ring with a toothing, the method comprising: ring rolling a pre-ring to form a ring blank; introducing a pre-toothing into the ring blank to form a pre-toothed ring, wherein the pre-toothing includes teeth with a first tooth height; heating, quenching, and tempering the pre-toothed ring to form a heat-treated pre-toothed ring; and finish-toothing the heat-treated pre-toothed ring to form a ring with a toothing, wherein the toothing includes teeth with a second tooth height that is greater than the first tooth height.

14. The method of claim 13 wherein at least one of the introducing of the pre-toothing or the finish-toothing of the heat-treated pre-toothed ring is performed by way of a metal machining process.

15. The method of claim 13 wherein the second tooth height is in a range of 50 mm to 125 mm.

16. The method of claim 13 wherein the second tooth height is in a range of 65 mm to 100 mm.

17. The method of claim 13 wherein the first tooth height is 50% to 95% of the second tooth height.

18. The method of claim 13 wherein the first tooth height is 75% to 85% of the second tooth height.

19. The method of claim 13 wherein the heating, quenching, and tempering comprises heating the pre-toothed ring as a whole to a temperature greater than 870 C.

20. The method of claim 13 wherein the heating, quenching, and tempering comprises heating the pre-toothed ring as a whole.

21. The method of claim 20 wherein the pre-toothed ring is quenched as a whole after the heating by placing the pre-toothed ring in a quenching bath.

22. The method of claim 20 wherein the pre-toothed ring is quenched as a whole after the heating.

23. The method of claim 22 wherein the pre-toothed ring is tempered after the quenching.

24. The method of claim 22 wherein after the quenching the pre-toothed ring is tempered at a temperature greater than 550 C.

25. The method of claim 22 wherein after the quenching the pre-toothed ring is tempered at a temperature greater than 580 C.

26. The method of claim 13 wherein the toothing is formed as an external toothing disposed on an outer periphery of the ring or an internal toothing disposed on an inner periphery of the ring.

27. The method of claim 13 wherein the toothing is a solid toothing that extends over at least one of an entire outer periphery of the ring or an entire inner periphery of the ring.

28. The method of claim 13 wherein the toothing is formed as at least one of a partial toothing that partially encircles an outer periphery of the ring or a partial toothing that partially encircles an inner periphery of the ring.

29. The method of claim 13 wherein the ring has a diameter in a range of 250 mm to 8000 mm.

30. The method of claim 13 wherein the ring has a diameter in a range of 2300 mm to 6000 mm.

31. The method of claim 13 comprising hardening the ring with the toothing in areas after the finish-toothing of the heat-treated pre-toothed ring.

32. The method of claim 13 comprising induction hardening the ring with the toothing in areas after the finish-toothing of the heat-treated pre-toothed ring.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0024] FIG. 1 shows a flow chart of a sample embodiment of a fabrication method according to the invention.

EMBODIMENTS OF THE INVENTION

[0025] FIG. 1 represents schematically the flow chart of a method according to the invention for the production of a seamlessly rolled ring with a toothing. The toothing may be formed as an external toothing provided on the outer periphery of the ring or as an internal toothing which is formed on the inner periphery of the ring. It is possible to configure the toothing as a solid toothing extending around the entire outer periphery and/or inner periphery of the ring or as a partial toothing which extends over only a portion of the outer periphery and/or inner periphery. The seamlessly rolled rings have a diameter in the range of 250 to 8000 mm, preferably in the range of 1800 mm to 7000 mm, especially preferably in the range of 2300 mm to 6000 mm. Rings with such diameters can be used as components of large gearings and large roller bearings for cranes, tunneling machines or wind power plants.

[0026] First of all, in a sawing step 1, individual rod-shaped sections 101 are sawn from rod stock 100, especially a rod-shaped steel. These rod-shaped sections 101 are heated in a heating step 2 and formed into a disk-shaped form 102 in a following upsetting step 3 by upsetting, especially by means of free-form or swaging presses or hammers. After this comes a hole punching step 4, in which the disk-shaped forms 102 are punched in their middle in order to produce an inside annular hole. The forms provided with an inside annular hole constitute so-called pre-rings 103.

[0027] Starting with a pre-ring 103, the production of a ring blank 104 occurs by ring rolling 5. For this, ring rolling mills are used in the form of a radial-axial ring rolling mill. Such ring rolling mills typically have two rolling gaps in which the height of the ring blank 104 and the wall thickness of the ring blank 104 are reduced at the same time. The production of a ring blank 104 by ring rolling affords the advantage of forming a tangential course of the fibers typical for rolled rings, producing isotropic tangential mechanical properties over the entire ring periphery.

[0028] As a departure from the representation in FIG. 1, the ring blank 104 can be additionally normalized. The normalization can be done at a temperature greater than or equal to 850 C., preferably greater than or equal to 860 C., especially preferably greater than or equal to 870 C. Moreover, the ring blank 104 may be rough-turned in a further optional step, in order to obtain a rectangular ring cross section.

[0029] According to the invention, the ring blank 104 is subjected to a pre-toothing step 6. In this process, a pre-toothing is introduced into the seamlessly rolled ring blank 104, wherein the pre-toothing has teeth with a first tooth height which is reduced in relation to the nominal tooth height of the final toothing. This pre-toothing is done by means of a metal machining process, such as by means of milling, especially by means of hobbing. Thanks to the pre-toothing 6, a pre-toothed ring 105 is formed from the ring blank.

[0030] Immediately after the pre-toothing 6, the pre-toothed ring 105 is heat treated by heating, quenching and tempering as a whole. In the course of the heating, quenching and tempering 7 the pre-toothed ring 105 as a whole is at first heated to a temperature in the range of greater than or equal to 850 C., preferably greater than or equal to 860 C., especially preferably greater than or equal to 870 C. The heating 7.1 is done for example by means of a furnace, a continuous annealing plant or a batch annealing plant. Directly after the heating 7.1 the pre-toothed ring is quenched as a whole, for example by placing the pre-toothed ring as a whole in a quenching bath, especially one consisting of water, oil, or a polymer quenching agent. In this process, the pre-toothed ring as a whole is hardened. After the quenching 7.2 comes a tempering step 7.3, in which the pre-toothed ring is tempered after the quenching 7.2 at a temperature greater than or equal to 550 C., preferably greater than or equal to 570 C., especially greater than or equal to 580 C. The tempering 7.3 completes the heating, quenching and tempering 7 of the pre-toothed ring 105.

[0031] The heat-treated and pre-toothed ring 106 is now finish-toothed by means of a metal machining process. In this process, the tooth height of the toothing is increased so that the second tooth height produced in the finish-toothing 8 is greater than the first tooth height obtained by the pre-toothing. Optionally, the inner periphery of the ring can be further increased by a lathe turning process.

[0032] The finish-toothed ring 107 is then hardened in certain areas, so that the strength of the ring is further increased in certain areas. The hardening 9 in certain areas is done by means of an induction hardening method followed by quenching with a spraying device. Preferably those regions of the ring 107 are hardened that are free of toothing. In the case of an external toothing, for example, the inner contour of the ring 107 may be hardened. In the case of a ring 107 with an internal toothing, the hardening in certain areas may occur on the outer periphery of the ring 107.

[0033] In the above described method for producing a ring with a toothing 108 the following steps are carried out:

[0034] (a) ring rolling 5 of a pre-ring 103 to form a ring blank 104,

[0035] (b) introducing a pre-toothing into the ring blank 104 to form a pre-toothed ring 105, wherein the pre-toothing has teeth with a first tooth height,

[0036] (c) heating, quenching and tempering 7 of the pre-toothed ring 105 to form a heat-treated pre-toothed ring 106, and

[0037] (d) finish-toothing 8 of the heat-treated pre-toothed ring 106 to form a ring with a toothing, wherein the toothing has teeth with a second tooth height, which is greater than the first tooth height. In this way, one can achieve improved strength in the region of the tooth base.

LIST OF REFERENCE NUMBERS

[0038] 1 Sawing [0039] 2 Heating [0040] 3 Upsetting [0041] 4 Hole punching [0042] 5 Ring rolling [0043] 6 Pre-toothing [0044] 7 Heating, quenching and tempering [0045] 7.1 Heating [0046] 7.2 Quenching [0047] 7.3 Tempering [0048] 8 Finish-toothing [0049] 9 Hardening [0050] 100 Rod-shaped stock [0051] 101 Rod-shaped section [0052] 102 Disk-shaped form [0053] 103 Pre-ring [0054] 104 Ring blank [0055] 105 Pre-toothed ring [0056] 106 Heat-treated pre-toothed ring [0057] 107 Finish-toothed ring [0058] 108 Hardened ring