METHOD FOR CREATING OR MACHINING GEARS AND GEAR-CUTTING MACHINE DESIGNED THEREFOR

Abstract

The invention relates to a method for creating or machining gears on workpieces (W1, W2), in which a rolling first machining engagement between a machining tool (WF; WS) that is driven about its rotation axis (B) and a first workpiece that is rotatable about the rotation axis (C1) of a first workpiece-side spindle (11) is realized at a first location on a gear-cutting machine (100; 200) by means of a tool-side spindle drive motor (22), and in which a second machining engagement is realized at a second workpiece, different from the first workpiece, that is rotatable about the rotation axis of a second workpiece-side spindle (12) that is different from the first workpiece-side spindle, wherein the machining tool can execute, relative to the first workpiece-side spindle, a movement, serving as an axial infeed movement in the first machining engagement, along a tool-side machine axis (Z) that has a direction component in the direction of the first workpiece-side spindle axis and in particular extends parallel thereto, wherein, after the first machining engagement, a tool-side positioning movement that takes place along this tool-side machine axis and allows the second machining engagement is carried out, wherein the second machining engagement is a machining engagement that is identical to the first machining engagement in terms of type of machining, is effected using the same tool-side spindle drive motor as in the first machining, and is carried out in the gear-cutting machine at a second point that is different from the first point.

Claims

1. A method for creating or machining gears on workpieces, in which a rolling first machining engagement between a machining tool (WF; WS) that is driven about its rotation axis (B) by means of a tool-side spindle drive motor (22), and a first workpiece (W1) that is rotatable about the rotation axis (C1) of a first workpiece-side spindle (11) is realized at a first location on a gear-cutting machine (100; 200) and in which a second machining engagement is realized at a second workpiece (W2), different from the first workpiece, that is rotatable about the rotation axis of a second workpiece-side spindle (12) that is different from the first workpiece-side spindle, wherein the machining tool can execute, relative to the first workpiece-side spindle, a movement, serving as an axial infeed movement in the first machining engagement, along a tool-side machine axis (Z) that has a direction component in the direction of the first workpiece-side spindle axis and extends parallel thereto, characterized in that, after the first machining engagement, a tool-side positioning movement that takes place along this tool-side machine axis (Z) and allows the second machining engagement is carried out, wherein the second machining engagement is a machining engagement that is identical to the first machining engagement in terms of type of machining, is effected using the same tool-side spindle drive motor as in the first machining, and is carried out in the gear-cutting machine at a second point that is different from the first point.

2. The method of claim 1, wherein the second machining engagement is performed with a machining tool, which rotates around the same rotation axis (B) as in the first machining engagement.

3. The method of claim 2, wherein the second machining engagement is performed with the same machining tool (WF; WS) as in the first machining engagement.

4. The method of claim 1 wherein during the first and/or second machining engagement, a workpiece-side feed motion along the workpiece-side machine axis occurs.

5. The method of claim 1 wherein the workpiece-side spindle axes (C1, C2) extend in a horizontal direction.

6. The method of claim 1 wherein the second workpiece spindle axis is parallel to the first tool-side machine axis.

7. The method of claim 1 wherein the first and/or second workpiece-side spindle is fixed in space.

8. The method of claim 1 wherein the first and/or second workpiece-side spindle is movable with a motion component along its axis (Z11, Z12).

9. The method of claim 1 wherein between both workpiece-spindles, a tailstock arrangement (13) is provided, which is spatially fixed and acting from both sides.

10. The method of claim 1 wherein on the first workpiece a successive secondary machining is performed in the same chuck as in the first machining engagement.

11. The method of claim 10, wherein the secondary machining unit (7) executing the secondary machining after the machining of the first workpiece is displaced in parallel to the tool-side machine axis for the secondary machining of the second workpiece (Z7).

12. The method of claim 10, wherein on the first workpiece a further machining engagement following the secondary machining takes place in the first location, which is of the same machining type as the first machining engagement, and which is performed by using the same tool-side spindle drive motor and the same machining tool as in the first machining engagement.

13. The method of claim 1 wherein the type of machining is a hob cutting or roll grinding.

14. A gear-cutting machine (100; 200), having a first workpiece spindle (11) for rotatably holding a first workpiece (W1) at a first location in the machine, a second workpiece spindle (12) for rotatably holding a second workpiece (W2) at a second location in the machine, and a tool-side spindle drive motor (22) for rotatably driving at least one machining tool (WF;WS), characterized by a tool-side machine axis (Z), which allows a movement of the machining tool relative to the first workpiece spindle, as well as a directional component in the direction of the axis of the first workpiece spindle, and parallel thereto, wherein the setting of this machine axis allows a rolling machining engagement, due to the use of the tool-side spindle drive motor, in a first actuation at the first location and a second actuation at the second location.

15. A gear-cutting machine having a control, which controls the machine for performing a method according to claim 1.

16. The gear-cutting machine of claim 14, wherein the first and second workpiece-side spindle axes are horizontal.

17. The gear-cutting machine of claim 14 wherein the first and/or second workpiece-side spindle axes are parallel to the tool-side machine axis.

18. The gear-cutting machine of claim 14 having a secondary machining unit (7) which may be moved in parallel to the machine axis, in order to perform, in a first displacement location, a secondary machining on the first workpiece and in a second displacement location, a secondary machining on the second workpiece.

19. The method of claim 5 wherein said spindle axes are coaxial.

20. The method of claim 10 wherein said secondary machining comprises a chamfering and/or deburring operation.

21. The gear-cutting machine of claim 14 wherein said at least one machining tool comprises a hob.

22. The gear-cutting machine of clam 16 wherein said spindle axes are coaxial.

23. The gear-cutting machine of claim 18 wherein said secondary machining unit comprises a chamfering and/or deburring unit.

Description

[0030] Further features, details and advantages of the invention will become apparent from the following description with reference to the accompanying figures, in which

[0031] FIG. 1 shows a detail of a perspective view of a hobbing machine,

[0032] FIG. 2 shows a detail of a perspective view of a second embodiment of a hobbing machine, and

[0033] FIG. 3 shows a detail of a perspective view of a rolling grinding machine.

[0034] FIG. 1 shows in detail a hobbing machine 100, on the machine bed 5 of which two workpiece spindles 11, 12 are arranged in a fixed position in space. Shown in FIG. 1 is the axis of rotation C11 of the first workpiece spindle 11, whose spindle axis extends horizontally. The spindle axis of the second workpiece spindle 12, whose axis of rotation is denoted by C12, also extends horizontally and coaxially with the first workpiece spindle axis. Hereinafter, these axes are referred to as C11 and C12 also in terms of their horizontal position. The distance between the respective mutually facing workpiece-holders is dimensioned to allow a collision-free workpiece change on a spindle while machining takes place on the other workpiece spindle, and that, regardless of the type of clamping parts used, still a space between two workpieces remains, which are clamped on both spindles, as shown in FIG. 1. The workpiece spindles 11, 12 each have their own drive, which is a CNC-controlled direct drive.

[0035] In the situation illustrated in FIG. 1, a disk-like workpiece W1 clamped on the first workpiece spindle 1 is machined by hobbing by a hob WF, shown only schematically, for producing a gear on the workpiece W1. The bearing of the hob head 20 with hob WF and its drive 22 is such that the following machine axis movements of the hob WF are possible:

[0036] the rotation of the hob WF about its axis of rotation B,

[0037] a tangential motion Y along the axial direction of the tool axis of rotation B.

[0038] The position of this axis is not fixed in space, since the hob head 20 may be pivoted by

[0039] a pivoting movement about a pivot axis A for pivoting the hob head

[0040] a movement along the axial axis Z, which allows a displacement of the hob head 20 along the direction of the spindle axis C11 and is used in the hobbing as a feed axis, and

[0041] a movement along a radial axis X orthogonal to the axis Z, which is orthogonal to the axis Z and the tool axis of rotation B in this embodiment.

[0042] Although this is no longer apparent from FIG. 1, the machine axes X, Z are provided by a sled assembly having an axial sled movable in the Z-direction and mounted on the machine bed 5, movable in the Z direction axial slide and mounted on the axial slide, and a radial sled movable in the X direction, on which, in turn the hob head 20 is pivotally mounted about the axis A.

[0043] By moving the hob head 20 from the position shown in FIG. 1 toward the workpiece spindle 12, the hob WF can also be brought into machining engagement with a workpiece W2 clamped on the second workpiece spindle 12.

[0044] Also shown in FIG. 1 is a chamfering and deburring unit 7 which can be moved along an axial axis Z7 running parallel to the axis Z and can chamfer the workpiece W1 clamped on the first workpiece spindle 11 in a first displacement position, and which can perform, in the second displacement position shown in FIG. 1 a chamfering machining on the workpiece W2 which is clamped on the second workpiece spindle 12. In the chamfering unit used in this embodiment, the chamfer is produced at the tooth edges of the workpieces by plastic deformation. The secondary burrs which are thereby thrown on the tooth flank can be eliminated by providing a second machine cut on the workpiece by the hob WF.

[0045] A preferred machining performed on the illustrated hobbing machine 100 may be as follows:

[0046] A workpiece changer, not shown, transfers a first workpiece W1 on the first workpiece spindle 11, where it undergoes a hobbing machining by the hob WF at a first machining point defined by the axial positioning in the Z direction. This corresponds to the representation of hob WF and workpiece W1 in FIG. 1.

[0047] After generating the gear on the workpiece W1 in the first machining step, the hob WF is moved to the second machining position to generate there a gear on the workpiece W2, which is clamped on the second workpiece spindle 12. Parallel to the hobbing machining of the second workpiece, by displacing the chamfering device 7 to its first position, a chamfering of the gear of workpiece W1 may be performed.

[0048] Subsequently, the hob WF returns to the first machining position, in order to remove the secondary burrs from the tooth flanks of the workpiece W1 in a second machining step, while the chamfering unit 7 is controlled to the second position to chamfer the gear edges of the workpiece W2.

[0049] Subsequently, on the first workpiece spindle 11, the workpiece W1 may be replaced by a subsequent workpiece (blank) W3 while the hob WF returns to the second machining position in order to perform the second cut on the workpiece W2.

[0050] Thus, the hob WF and the chamfering unit 7 are axially displaced between their respective machining, in a push-pull way.

[0051] The embodiment shown in FIG. 2 is similar in many respects to the first embodiment shown in FIG. 1. Thus, the tool-side structure is the same, and reference is made in this regard to the above description. However, the workpiece spindles 11, 12 are not spatially fixed, but have a respective axial movement axis Z11 and Z12. In addition, between the two workpiece spindles 11, 12 a tailstock assembly 13 is arranged which is spatially fixed, which acts on both sides, so as to form a tailstock for both the first workpiece spindle 11 and for the second workpiece spindle 12. The second embodiment is thus also suitable for the hobbing of shafts but is also suitable as the first embodiment for disc-like workpieces. With regard to the process design with the first cut, chamfering and second cut, the same procedure can be followed as according to the above description of the first embodiment.

[0052] FIG. 3 shows a detail of a hobbing machine 200. Here, the machining head 40 carries a grinding worm WS. With regard to the machine axes, the same machine axes are provided as previously described with reference to FIG. 1. The workpiece spindles 11 and 12 are similar in this embodiment as described in the second embodiment described by means of FIG. 2, and also the double-sided tailstock assembly 13 is provided. The grinding worm WS machines the first hardened workpiece W1 already provided with a gear to eliminate hardness distortions and remove the intended thickness to the desired nominal geometry of the gear. During the machining of the grinding worm WS on the workpiece W1 clamped on the first workpiece spindle 11, a workpiece replacement of an already ground workpiece with a workpiece still to be ground can take place on the second workpiece spindle 12 and vice versa.

[0053] Not shown in FIG. 3 is a device for centering/Indexing of the gear, which is preferably provided in the form of a centering sensor, which is known to those skilled in the art. In one variant, one sensor may be provided for each workpiece spindle and may be movably arranged by a suitable positioning device for sensor detection of the rotational position of the geared workpieces.

[0054] In an alternative embodiment only one sensor may be provided, which, like the chamfering device 7 of the examples with the embodiments of hobbing machines, is movably mounted and alternately drives the workpiece clamped on the first workpiece spindle 11 and the second workpiece spindle 12 for the purpose of centering the same.

[0055] The invention is not limited to the details described in the above examples. Rather, the particular features of the above description as well as the following claims may be considered to be essential, both individually and in combination, to the practice of the invention in its various embodiments.