Abnormality diagnostic method for feed axis and abnormality diagnostic device for the same

An abnormality diagnostic device for feed axis, in a machine including a feed axis that moves a moving body via a ball screw that rotates by a servo motor, the device comprising:

• a storing unit that stores a frequency characteristic of the feed axis and a damage frequency that occurs when the feed axis that has been damaged performs an axis operation;
• a feed velocity calculating unit that calculates a feed velocity configured to detect a peak of the damage frequency from the stored frequency characteristic;
• an axis operation performing unit that performs the axis operation on the feed axis with the calculated feed velocity;
• a frequency analysis unit that performs a frequency analysis on servo information regarding a control of the servo motor during the axis operation;
• and
• a determining unit that confirms the presence and absence of the peak of the damage frequency from a result of the frequency analysis to determine the abnormality when the peak is present.