Gear-cutting machine

A gear cutting machine comprising:

• a cutter;
• a cutter spindle motor configured to cause, via a crank mechanism and a cutter spindle, the cutter to perform a stroke operation in a direction of the cutter spindle;
• and
• a motor control unit configured to control a rotation angle of the cutter spindle motor, wherein
• the gear cutting machine comprises a relieving spindle motor configured to cause the cutter to move in a direction of a relieving spindle via a link mechanism,
• the motor control unit controls a rotation angle of the relieving spindle motor based on the rotation angle of the cutter spindle motor, and
• the motor control unit
• determines a track of the cutter on x-y coordinates from tracks of the cutter on x-θcoordinates and on y-θcoordinates, where θis the rotation angle of the cutter spindle motor, the y-axis direction is the direction of the cutter spindle, and the x-axis direction is the direction of the relieving spindle,
• determines an inclination angle of the cutter from the track of the cutter on the x-y coordinates,
• determines an output angle of the link mechanism from the inclination angle, and
• determines an input angle of the link mechanism from the output angle, so that the motor control unit controls the rotation angle of the relieving spindle motor.