A method for producing a milling tool with cutting teeth includes the steps: defining a tooth profile to be machined with the milling tool from a workpiece to be processed to produce a gear tooth; determining a cutting tooth geometry, including the cutting edges of the cutting tooth geometry, with which the defined tooth profile to be machined in the workpiece to be processed can be machined using a milling process; subdividing the cutting tooth geometry into at least two different partial cutting tooth geometries, wherein the different partial cutting tooth geometries are configured such that at least one of the partial cutting tooth geometries has portions which recess behind the outer contour of the cutting tooth geometry and that the superposition of the different partial cutting tooth geometries reproduces the cutting tooth geometry; providing a milling tool blank; and machining of cutting teeth from the milling tool 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.

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.

By combining shaping and milling actions, or smilling, the cutting tool can move through the entire usable portion of the spline and machine a tool relief into the face of the adjacent feature such as a shoulder before retracting, reversing direction, and repeating the cycle. The smilling apparatus and manufacturing method eliminates the need for an annular spline relief and the full length of spline engagement can be utilized for strength. The effective width of the spline connection apparatus manufactured by the smilling process conserves space and increases the load carrying capability of the spline connection.

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.

Generating cutting processes for producing bevel gears and employing a single rotary disc cutter (36) wherein a portion of the generating cutting process effectively includes a reduction (38) of the workpiece roll angle (40) during generating thereby reducing or eliminating cutting action on the clearance side (42) of the rotary disc cutter.

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.

A gear machining apparatus causes a machining tool and a workpiece to rotate at a high speed in synchronization with each other to machine a highly accurate gear through cutting. The machining tool is manufactured such that each of pitches between tool blades of the machining tool is an integer multiple of a pitch between teeth of the gear, the integer multiple being equal to or larger than double. By using the machining tool for cutting performed by the gear machining apparatus, the number of the tool blades of the machining tool, which are brought into contact with the workpiece at the same time, is reduced. Thus, it is possible to suppress occurrence of self-excited vibrations during cutting by reducing the cutting resistance. Thus, it is possible to enhance the tooth trace accuracy of the gear.