The invention discloses a method for producing modifications, such as twists, on the tooth flanks of an internally-toothed workpiece by an externally-toothed tool. In order to carry out such a method also with machine tools, which have a reduced number of adjustable axes, the invention provides that the tool is dressed by arranging an internally-toothed dressing tool on the workpiece spindle of the machine tool at the position intended for the workpiece to be respectively honed and by bringing the dressing tool into engagement with the tool to be dressed. The width of the teeth of the dressing tool is smaller than the width of the tool to be dressed such that the dressing tool must be moved by a length along the workpiece longitudinal axis which corresponds to a multiple of the width of the teeth of the dressing tool. Subsequently, the fine machining of the workpiece takes place with the tool dressed in this manner. According to the invention, an axis cross angle is set for the dressing, which is maintained unchanged during the dressing. The respective tooth flank modification is then produced during dressing exclusively by movements of the dressing tool along the workpiece longitudinal axis and the workpiece transverse axis.

A shaving processing method and apparatus for a gear are provided which reduce a load at the time of processing a tooth surface, thereby reducing a transmission error of the gear. Embodiments include a method for finishing the tooth surface of the gear in a state where the gear and a shaving cutter are engaged with each other and the shaving cutter is rotated. The gear has a pair of end surfaces facing each other in the tooth width direction. A first shaving step of processing the tooth surface is performed so that a processing region gradually expands from one end surface of the pair of end surfaces toward the other end surface, and a second shaving step of processing the tooth surface is performed so that a processing region gradually expands from the other end surface of the pair of end surfaces toward the one end surface.

The present disclosure provides a method for manufacturing a gear capable of processing a projection formed on a tooth tip by shot peening while reducing time for manufacturing the gear. A method for manufacturing a gear includes: a process of hardening, by performing shot peening in which shot particles are jetted onto a tooth surface 1a of a gear base material, the tooth surface while applying residual stress to the tooth surface; a process of softening, by at least heating a tooth tip of the gear base material having the hardened tooth surface, the tooth tip; and a process of rotationally driving the gear base material having the softened tooth tip by engaging it with another gear.

A shaving processing method and apparatus for a gear are provided which reduce a load at the time of processing a tooth surface, thereby reducing a transmission error of the gear. Embodiments include a method for finishing the tooth surface of the gear in a state where the gear and a shaving cutter are engaged with each other and the shaving cutter is rotated. The gear has a pair of end surfaces facing each other in the tooth width direction. A first shaving step of processing the tooth surface is performed so that a processing region gradually expands from one end surface of the pair of end surfaces toward the other end surface, and a second shaving step of processing the tooth surface is performed so that a processing region gradually expands from the other end surface of the pair of end surfaces toward the one end surface.

A gear cutting tool wherein each cutting blade group includes two differently positioned but identical cutting blades (41, 40) such as an one outside and one inside blade. The inventive blade arrangement only requires a single type of blade (30) in order to simultaneously cut the convex and the concave tooth flanks of a gear as well as the root fillet and root bottom portions of tooth slots. The cutter system allows radial adjustment of the outside cutting blade and the inside cutting blade independently of one another. Additionally, inside and outside cutting blades may be exchanged with one another.

The present disclosure provides a method for manufacturing a gear capable of processing a projection formed on a tooth tip by shot peening while reducing time for manufacturing the gear. A method for manufacturing a gear includes: a process of hardening, by performing shot peening in which shot particles are jetted onto a tooth surface 1a of a gear base material, the tooth surface while applying residual stress to the tooth surface; a process of softening, by at least heating a tooth tip of the gear base material having the hardened tooth surface, the tooth tip; and a process of rotationally driving the gear base material having the softened tooth tip by engaging it with another gear.

A gear cutting tool wherein each cutting blade group includes two differently positioned but identical cutting blades (41, 40) such as an one outside and one inside blade. The inventive blade arrangement only requires a single type of blade (30) in order to simultaneously cut the convex and the concave tooth flanks of a gear as well as the root fillet and root bottom portions of tooth slots. The cutter system allows radial adjustment of the outside cutting blade and the inside cutting blade independently of one another. Additionally, inside and outside cutting blades may be exchanged with one another.

To provide a gear machining device and a gear machining method which achieve machining of tooth flanks having different torsion angles with high degree of accuracy. In a gear machining device, a side surface of a tooth of a gear includes a first tooth flank and a second tooth flank having a different torsion angle from the first tooth flank, a cutting blade of a machining tool has a blade traces having a torsion angle determined based on a torsion angle of the second tooth flank and an intersection angle between a rotation axis of a workpiece and a rotation axis of the machining tool so as to allow the second tooth flank to be machined on the pre-machined first tooth flank.