A hob for a cutting apparatus including a hollow body of a sintered hard metal composition and a cavity located within the body, the cavity having a volume in the range of about 10% to about 90% of the volume of the body.

A skiving cutter includes a cutting edge portion in which a tooth trace extends in a direction inclined with respect to an axis of a base. The cutting edge portion is segmented into a plurality of segmented cutting edges by cutting edge grooves extending in a direction intersecting the tooth trace. A helix angle is different according to positions of the plurality of segmented cutting edges.

A tool head for a machine tool, in particular for a gear cutting machine, has a first and a second spindle unit each having at least one spindle bearing and a spindle shaft which is rotatably mounted in the respective spindle bearing about a tool spindle axis. The respective spindle bearing can support both radial and axial forces. The spindle units are arranged coaxially to each other, and a tool is received axially between the spindle shafts. A controlled clamping device connects the spindle bearings together. A control device activates the clamping device during a machining operation and deactivates it during machining pauses. Alternatively or additionally, the tool head has an axial force element that generates an axial preload force between the spindle bearings.

A tool changer is used for changing tools in a machine tool. The tool changer has a support structure on which a lifting carriage is guided along a vertical lifting direction. A pivot arm is pivotably mounted to the lifting carriage about a vertical pivot axis. A plurality of tool holders arranged vertically one above the other form a tool magazine. A tool gripper is attached to the pivot arm. The tool gripper grips a tool. The tool is subsequently moved between one of the tool holders and the tool spindle of the machine tool by a combined lifting and pivoting movement of the pivot arm. Optionally, an auxiliary arm pivotably attached to the pivot arm can be used to change a workpiece clamping means of the machine tool.

A tool head for a gear cutting machine includes a first spindle unit having a first spindle shaft and a second spindle unit having a second spindle shaft. A tool is axially receivable between the first spindle shaft and the second spindle shaft. A balancing device is associated with each spindle unit. The balancing device radially surrounds the respective spindle shaft and is axially arranged between a tool-side spindle bearing of the corresponding spindle unit and the tool-side end of the corresponding spindle shaft. The tool is axially clamped between the two spindle shafts by a pull rod and a clamping element.

A skiving cutter includes a cutting edge portion in which a tooth trace extends in a direction inclined with respect to an axis of a base. The cutting edge portion is segmented into a plurality of segmented cutting edges by cutting edge grooves extending in a direction intersecting the tooth trace. One of the plurality of segmented cutting edges forms a reference cutting edge. Among the plurality of segmented cutting edges constituting the cutting edge portion, the reference cutting edge has the largest axis-cutting edge distance which is a distance from the axis to the outer circumferential cutting edge of the segmented cutting edge, and the remaining one or more segmented cutting edges have gradually smaller axis-cutting edge distances as a distance from the reference cutting edge to each of the remaining cutting edges increases. A helix angle is different according to positions of the plurality of segmented cutting edges.

A gear cutting machine for gear cutting a workpiece (W) using a gear shaped cutter (17), by engaging and rotating the workpiece (W) that can rotate around a workpiece axis and a gear shaped cutter (17) that can rotate around a cutter axis, while cutting and feeding the gear shaped cutter (17), including: rough cutting at a cross axis angle to the cutter axis, then moving the cutter axis by moving a predetermined angle around the workpiece axis, and performing finish cutting such that the cutter axis has an angle with regard to the workpiece axis in a plane that includes the feeding axis direction and the cutting direction after moving.

A skiving cutter includes a cutting edge portion in which a tooth trace extends in a direction inclined with respect to an axis of a base. The cutting edge portion is segmented into a plurality of segmented cutting edges by cutting edge grooves extending in a direction intersecting the tooth trace. One of the plurality of segmented cutting edges forms a reference cutting edge. Among the plurality of segmented cutting edges constituting the cutting edge portion, the reference cutting edge has the largest axis-cutting edge distance which is a distance from the axis to the outer circumferential cutting edge of the segmented cutting edge, and the remaining one or more segmented cutting edges have gradually smaller axis-cutting edge distances as a distance from the reference cutting edge to each of the remaining cutting edges increases. A helix angle is different according to positions of the plurality of segmented cutting edges.

A gearbox repair assembly is disclosed herein. The gearbox repair assembly includes a sleeve having an inner diameter configured to receive a bearing assembly and an outer diameter configured to fit within a bore of a gearbox housing. The gearbox housing can be part of a gearbox of a wind turbine. The gearbox repair assembly further includes a retaining plate configured to be attached to the gearbox housing for preventing an outer race of the bearing assembly from rotating in the bore relative to the gearbox housing. Also provided are methods to repair such a gearbox. The gearbox repair assembly and related methods reduce the time and cost needed to repair the gearboxes.

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.