Gear cutting tool, gear machining apparatus, and gear machining method

A gear machining apparatus configured to generate a gear tooth to a workpiece, the gear machining apparatus comprising:

• a rough working tool having a ring-shaped tool main body, and a plurality of tool blades which are replaceable and attached to the tool main body, such that the tool blades are arranged in a circumferential direction of the tool main body and a blade tip of each of the tool blades is oriented inward in a radial direction of the tool main body;
• a finish working tool having a ring-shaped tool main body, and a plurality of tool blades which are provided to the tool main body, such that the tool blades are arranged in the circumferential direction of the tool main body and the blade tip of each of the tool blades is oriented inward in the radial direction of the tool main body;
• a tool spindle which rotatably supports each of the rough working tool and the finish working tool;
• a workpiece spindle which rotatably supports the workpiece and is relatively movable to the tool spindle;
• a tool magazine which is capable of housing the rough working tool and the finish working tool;
• a tool replacing unit which is configured to replace the rough working tool and the finish working tool with respect to the tool spindle;
• a rough machining control unit which is configured to control to perform a rough machining on the workpiece, such that the rough working tool is rotated on a center line in an axial direction of the rough working tool, the workpiece is rotated on a center line in an axial direction of the workpiece, and the rough working tool is relatively moved to the workpiece along the center line in the axial direction of the workpiece;
• and
• a finish machining control unit which is configured to control to perform a finish machining on the workpiece, such that the finish working tool is rotated on a center line in an axial direction of the finish working tool, the workpiece is rotated on the center line in the axial direction of the workpiece, and the finish working tool is relatively moved to the workpiece along the center line in the axial direction of the workpiece.

A gear machining method of generating a gear tooth to a workpiece, comprising:

• performing a rough machining on the workpiece, by rotating a rough working tool on a center line in an axial direction of the rough working tool, rotating the workpiece on a center line in an axial direction of the workpiece, and relatively moving the rough working tool to the workpiece along the center line in the axial direction of the workpiece, the rough working tool having a ring-shaped tool main body and a plurality of the tool blades which are replaceable and attached to the tool main body, such that the tool blades are arranged in the circumferential direction of the tool main body and a blade tip of each of the tool blades is oriented inward in the axial direction of the tool main body;
• and
• performing a finish machining on the workpiece such that the gear tooth is generated, by rotating the finish working tool on a center line in an axial direction of the finish working tool, rotating the workpiece on the center line in the axial direction of the workpiece, and relatively moving the finish working tool to the workpiece along the center line in the axial direction of the workpiece, after replacing the rough working tool with a finish working tool, the finish working tool having a ring-shaped tool main body and a plurality of tool blades that are provided to the tool main body, such that the tool blades are arranged in the circumferential direction of the tool main body and the blade tip of each of tool blades is oriented inward on the radial direction of the tool main body.