A combined gear cutting apparatus includes a workpiece drive portion, a first processing portion holding and moving a first tool to a processing position for a workpiece, a second processing portion holding and moving a second tool to a processing position for the workpiece, and a control portion which includes a storage portion storing workpiece information indicating a configuration of the workpiece before first processing is performed, first tool information, second tool information and relative position information. The control portion includes a tooth groove configuration calculation portion calculating tooth groove configuration information of the workpiece based on the first tool information, the workpiece information and the relative position information obtained when the first processing is completed. The second tool is configured to move to a start position of second processing for the workpiece based on the tooth groove configuration information, the second tool information and the relative position information.

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.

A method for producing gears, wherein in a first step a set of teeth is formed by means of a skiving wheel rotationally driven by a tool spindle in a workpiece gear rotationally driven synchronously thereto by a workpiece spindle, wherein the workpiece spindle and the tool spindle are at an axis intersection angle to each other and the advancement occurs in the tooth-flank extension direction, and wherein in a second step at least some teeth of the set of teeth are machined by means of a tooth-machining tool. A combined tool is used, in the case of which the toothmachining tool and the skiving wheel are fixedly connected to each other. Between the two steps, the combined tool remains connected to the tool spindle and the workpiece gear remains connected to the workpiece spindle. Between the two steps, merely the relative position of the tool spindle in relation to the workpiece spindle and the rotational speed ratio of the two spindles are changed.

A gear machining apparatus includes a machining tool having a plurality of protruding tool edges on an outer periphery of the machining tool, and driving apparatuses that form a tooth on a work piece by rotating the machining tool around a central axis thereof, rotating the work piece W around a central axis thereof, and moving the machining tool relative to the work piece. Radial outer faces of the protruding tool edges form multiple steps that are parallel to the central axis of the machining tool such that the diameter of the machining tool increases in a stepwise manner from a tool leading end toward a tool base end of the machining tool.

The present invention achieves a machining apparatus which can easily be composed and a machining method which can perform gear machining or splined shaft machining easily by using an existing lathe. More specifically, the invention achieves a machining apparatus 1 comprising: a cutter 11 which includes a blade part 20 formed in the shape of a ring around a peripheral surface thereof and which is driven to rotate about an axis thereof; a workpiece holder 13 which holds a workpiece W rotatably; and a cutter driver 12 which moves the cutter 11 and the workpiece W relative to each other along an axial direction, wherein a gear or a splined shaft is formed on the peripheral surface of the workpiece W by synchronizing the rotation of the workpiece W with the relative movement of the cutter 11 and the workpiece W and by rotating the cutter 11, and wherein a plurality of the blade parts 20 are disposed side by side along the axis, the cutter driver 12 drives the cutter 11 to rotate in one direction around the axis and to reciprocate relative to the workpiece W along the axis, the workpiece holder 13 rotates the workpiece W in a forward/reverse direction in accordance with reciprocation of the cutter 11, and cutting is performed on the workpiece W so as to form thereon an external shape of a gear or a splined shaft by placing each of the blade parts 20 of the cutter 11 in contact with the peripheral surface of the workpiece W.

The invention relates to a machine for the gear cutting machining of workpieces, in particular a gear shaping machine, comprising a spindle for holding a machining tool, and a drive by means of which the spindle can be rotationally driven about its spindle axis, and further comprising an arrangement. When said arrangement is actuated, a spindle rotation caused by the drive changes the axial relative position with respect to the spindle axis.

The present invention achieves a machining apparatus which can easily be composed and a machining method which can perform gear machining or splined shaft machining easily by using an existing lathe. More specifically, the invention achieves a machining apparatus 1 comprising: a cutter 11 which includes a blade part 20 formed in the shape of a ring around a peripheral surface thereof and which is driven to rotate about an axis thereof; a workpiece holder 13 which holds a workpiece W rotatably; and a cutter driver 12 which moves the cutter 11 and the workpiece W relative to each other along an axial direction, wherein a gear or a splined shaft is formed on the peripheral surface of the workpiece W by synchronizing the rotation of the workpiece W with the relative movement of the cutter 11 and the workpiece W and by rotating the cutter 11, and wherein a plurality of the blade parts 20 are disposed side by side along the axis, the cutter driver 12 drives the cutter 11 to rotate in one direction around the axis and to reciprocate relative to the workpiece W along the axis, the workpiece holder 13 rotates the workpiece W in a forward/reverse direction in accordance with reciprocation of the cutter 11, and cutting is performed on the workpiece W so as to form thereon an external shape of a gear or a splined shaft by placing each of the blade parts 20 of the cutter 11 in contact with the peripheral surface of the workpiece W.

A method for skiving machining a toothed workpiece includes the steps of: providing the toothed workpiece rotatable about a workpiece axis; providing a toothed tool rotatable about a tool axis; tilting the tool axis through an azimuth angle >0 with respect to an x direction; tilting the tool axis furthermore through a polar angle <90 with respect to a z direction; rotating the toothed tool about the tool axis, the toothed tool in a contact zone sliding over the toothed workpiece rotating about the workpiece axis. The workpiece axis defines the x direction and the perpendicular of the contact zone to the workpiece axis defines a z direction. The x direction, a y direction and the z direction form a Cartesian coordinate system. This method can easily produce a chamber on the toothed workpiece with the toothed tool which is subject to fewer geometric restrictions.

A machine tool and method for incorporating undercuts in left and right tooth flanks of teeth of a toothed gear blank by hob peeling, wherein the gear blank and a cutting wheel having cutting teeth with right and left cutting edges arranged at an axis intersection angle to the gear blank are continuously rotationally driven at a fixed speed ratio, the cutting teeth engage in the tooth flanks in a manner that removes shavings and the feed has at least one movement component in the direction of extension of the teeth of the gear blank.

A gear machining apparatus includes a machining tool having a plurality of protruding tool edges on an outer periphery of the machining tool, and driving apparatuses that form a tooth on a work piece by rotating the machining tool around a central axis thereof, rotating the work piece W around a central axis thereof, and moving the machining tool relative to the work piece. Radial outer faces of the protruding tool edges form multiple steps that are parallel to the central axis of the machining tool such that the diameter of the machining tool increases in a stepwise manner from a tool leading end toward a tool base end of the machining tool.