the invention relates to a method for machining or producing a toothed portion (2) on a workpiece by means of a tool toothed portion (4), wherein the tool toothed portion is brought into a first machining engagement with the rotating workpiece toothed portion clamped in a clamped setup, such that there is rolling coupling which assigns the teeth of the tool toothed portion to the tooth spaces of the workpiece toothed portion, and wherein the tool toothed portion is brought into a second machining engagement phase-shifted by at least one fourth of the pitch in comparison with the rolling coupling of the first machining engagement at the machining distance of deepest advancement, said second machining engagement having increased machining distance from the workpiece toothed portion clamped in the same clamped setup of the first machining engagement in comparison with the deepest advancement of the first machining engagement. The invention also relates to a control program having control instructions, which, when executed on a controller of a gear cutting machine, cause said gear cutting machine to carry out the method. The invention also relates to a gear cutting machine therefor.

A machine tool that generates internal teeth or external teeth on a cylindrical workpiece includes a workpiece holder, a column which is relatively movable to the workpiece holder, a rotary main spindle which is rotatable with respect to the column, a working tool which is held by the rotary main spindle, and a phase detecting unit which detects a phase of the working tool with respect to the rotary main spindle. The working tool includes a cutter portion which has cutters, a holder portion, and a detected portion which is formed on the holder portion. The phase detecting unit includes a detecting section which detects the detected portion, and a calculating section which calculates a phase angle of the detected portion with respect to a reference position of the rotary main spindle, based on a result detected by the detecting section.

A power skiving method wherein three-dimensional cutter rotations relative to gear workpiece tooth flank surfaces are carried out so as to reposition the cutter relative to a gear workpiece so as to achieve a decrease and/or an increase in the pressure angle of the tooth flank surfaces. The method can be applied independently to left and right flank surfaces of a tooth slot or the rotations may be superimposed on one another to realize pressure angle corrections on both tooth flanks of a tooth slot.

A gear machining apparatus includes a rough working tool having a plurality of replaceable tool blades attached to a tool main body, such that the tool blades are arranged in a circumferential direction of the tool main body and blade tips of the tool blades are oriented outward in a radial direction of the tool main body, a finish working tool having a plurality of tool blades provided to a tool main body in a similar manner to the rough working tool, and machining controllers control to perform rough and finish machinings on the workpiece, such that the working tools are rotated on center lines in axial directions of the working tools, the workpiece is rotated on a center line in axial direction of the workpiece, and the working tools are relatively moved to the workpiece along the center line in the axial direction of the workpiece.

The invention relates to a method for machining the tip circle diameter of a tooth system (4) of a gearwheel (6), in which the gearwheel (6) rotates about a workpiece axis of rotation (Rw), and in which at least one tooth (9) of the tooth system (4) is machined, by removing chips, by means of a tool (7, 7′) that rotates about a tool axis of rotation (Rz) oriented at an axial distance (A′, A″) relative to the workpiece axis of rotation (Rw). According to the invention, the tool (7, 7′) is disk-shaped, the disk-shaped tool (7, 7′) machines the tip surface (8) of the tooth (9), by removing chips, with at least one partial segment (10a) of its circumferential edge configured as a defined blade (10), wherein a relative movement between the tool (7, 7′) and the gearwheel (6), oriented in the axial direction of the tooth system (4), is carried out during the chip-removing machining, as a consequence of which movement the tool (7, 7′) sweeps over the tip surface (8), and the tool axis of rotation (Rz) is oriented at an axis intersection angle (Σ″) of 5° to 40° with respect to the workpiece axis of rotation (Rw). In this way, efficient and highly precise machining of the tip circle diameter is made possible. The invention also states a method for producing a gearwheel, in which the tooth system (4) is produced on a gearwheel blank (5) by means of hob peeling before machining of the tip circle diameter according to the invention, as well as a combination tool, in which a hob-peeling wheel for producing the gearwheel and a disk-shaped tool for machining the tip circle diameter according to the invention are combined with each other.

In a gear skiving process method, a tooth-cutting process is performed on a surface to be cut of a workpiece using a first skiving cutter disposed at a first processing position on the surface to be cut and a second skiving cutter disposed at a second processing position set apart by 180° in a circumferential direction from the first processing position. Parts that are to be right tooth flanks of internal teeth to be created in the surface to be cut of the workpiece are cut mainly by the first skiving cutter. Additionally, parts that are to be left tooth flanks are cut mainly by the second skiving cutter. Conditions of the processing performed using the first and second skiving cutters can be controlled individually and teeth having a shape in which the left and right tooth flanks are different can be processed efficiently.

A power skiving method wherein three-dimensional cutter rotations relative to gear workpiece tooth flank surfaces are carried out so as to reposition the cutter relative to a gear workpiece so as to achieve a decrease and/or an increase in the pressure angle of the tooth flank surfaces. The method can be applied independently to left and right flank surfaces of a tooth slot or the rotations may be superimposed on one another to realize pressure angle corrections on both tooth flanks of a tooth slot.

A machine tool is designed for the machining of rotary parts with groove-shaped profiles, in particular gears, by a generating method. On the one hand, a Y slide (200) is arranged on a machine bed (100), the Y slide being displaceable along a Y direction and carrying a workpiece spindle (210). The workpiece spindle drives a workpiece (220) to rotate about a workpiece axis (C). On the other hand, a Z slide (300) is arranged on the machine bed. The Z slide is arranged along a Z direction running parallel to a center plane (E1) spanned by the Y direction and the workpiece axis. An X slide (310) is arranged on the Z slide and can be displaced along an X direction relative to the Z slide (300). The X direction is perpendicular to the center plane. A tool spindle (320) is arranged on the X slide, which drives a tool to rotate about a tool axis. The tool spindle can be swiveled relative to the X slide in a swivel plane (E2), which runs parallel to the center plane, about a swivel axis (A).

The invention relates to a method for producing tooth flank modifications on toothing of workpieces, in which the workpiece and a tool are moved relative to one another and, as a result, material is removed from the tooth flank (3) of the workpiece. Different tooth flank modifications are generated on teeth (1) of the workpiece by means of a continuously rolling manufacturing process, by the tool comprising individually different tool profile geometries which generate the different tooth flank modifications on the teeth (1) of the workpiece. The tool can be a dresser with variable profile in order to provide, with dressable tools, individually different tool profile geometries.

A method for hard finishing two different toothings on a workpiece, wherein, prior to each machining process, to set the correct tool engagement position for the machining process, a first relative rotational angle position of a first rotational position reference of the first toothing is determined relative to an axial rotational position of the workpiece spindle holding and clamping the workpiece for the first machining, and a second relative rotational angle position of a second rotational position reference of the second toothing is determined relative to an axial rotational position of a workpiece spindle holding and clamping the workpiece for the second machining, wherein the machining operations are carried out on the same workpiece spindle with no intervening clamping change, and with the first and second rotational position references coupled to each other as the basis thereof.