The present disclosure relates to an apparatus for chamfering at least one edge of the gearing at the front side of a workpiece having internal gearing comprising at least one rotatably supported workpiece holder for holding the workpiece and comprising at least one rotatably supported tool holder for holding a chamfer hob, possibly a chamfer cut hob, wherein the tool holder is arranged at an internal hob arm whose free end can be traveled by a machine axis of the apparatus at least partly into the center opening formed by the internal gearing of the workpiece.

The present disclosure relates to an apparatus for chamfering at least one edge of the gearing at the front side of a workpiece having internal gearing comprising at least one rotatably supported workpiece holder for holding the workpiece and comprising at least one rotatably supported tool holder for holding a chamfer hob, possibly a chamfer cut hob, wherein the tool holder is arranged at an internal hob arm whose free end can be traveled by a machine axis of the apparatus at least partly into the center opening formed by the internal gearing of the workpiece.

A gear machining method includes: roughing a workpiece while causing a cylindrical hob cutter to rotate in synchronization with a rotation of the workpiece such that a cutting allowance remains; and finishing by cutting off the cutting allowance remaining on the workpiece on which the roughing has been performed during the roughing to form a desired gear shape by feeding a skiving cutter relatively to the workpiece in the rotation axis direction of the workpiece while causing the skiving cutter to rotate in synchronization with the rotation of the workpiece.

A gear machining method includes: roughing a workpiece while causing a cylindrical hob cutter to rotate in synchronization with a rotation of the workpiece such that a cutting allowance remains; and finishing by cutting off the cutting allowance remaining on the workpiece on which the roughing has been performed during the roughing to form a desired gear shape by feeding a skiving cutter relatively to the workpiece in the rotation axis direction of the workpiece while causing the skiving cutter to rotate in synchronization with the rotation of the workpiece.

A hobbing tool includes a hob body having at least one axially extending slot, and at least one cassette removably disposed in the at least one slot. The at least one cassette includes at least one seating recess having at least a bottom abutment surface and two side abutment surfaces. At least one cutting insert is removably mounted in the at least one seating recess. The at least one cutting insert has at least one bottom supporting surface and two side supporting surfaces that abut the bottom abutment surface and the two side abutment surfaces when the at least one cutting insert is received in the at least one seating recess. The hob body includes a plurality of axially extending slots. The hobbing tool also includes a corresponding plurality of cassettes removably mounted in the plurality of axially extending slots. Each cassette of the plurality of cassettes is identical to every other cassette of the plurality of cassettes.

A machine tool includes a workpiece holder, a tool holder holding working tools that includes a hob cutter used in a rough machining and a skiving cutter used in a finish machining, a tool magazine, a tool replacing device replacing one of the working tools mounted on the tool holder with the other of working tools housed in the tool magazine, a rough machining controlling section performing the rough machining on the workpiece, a tool measuring device measuring a position of a blade in a rotation direction of the skiving cutter, an angle correcting section correcting a rotation angle of the skiving cutter based on a result measured by the tool measuring device, and placing a tooth space formed in the workpiece and an edge tip of the blade in a position corresponding to each other, and a finish machining controlling section by which workpiece is finish machined.

A machine tool includes a workpiece holder, a tool holder holding working tools that includes a hob cutter used in a rough machining and a skiving cutter used in a finish machining, a tool magazine, a tool replacing device replacing one of the working tools mounted on the tool holder with the other of working tools housed in the tool magazine, a rough machining controlling section performing the rough machining on the workpiece, a tool measuring device measuring a position of a blade in a rotation direction of the skiving cutter, an angle correcting section correcting a rotation angle of the skiving cutter based on a result measured by the tool measuring device, and placing a tooth space formed in the workpiece and an edge tip of the blade in a position corresponding to each other, and a finish machining controlling section by which workpiece is finish machined.

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 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 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.