Patent ID: 11868123
Assignee: OKUMA CORPORATION
Field: Machine tools (Mechanical engineering)
Classification: CPC G  B | IPC B  G

Claim 3:
4. The abnormality diagnostic device for the feed axis mechanism according to claim 2, wherein
the diagnosis unit uses a second-order approximation formula as the approximation formula and diagnoses an abnormality in the teed axis mechanism as an abnormality due to a local abrasion of a screw shaft when a coefficient of the second-order approximation formula becomes negative,
when the stroke position having the maximum value in the second-order approximation formula is on a coupling side relative to a center of the stroke, the diagnosis unit diagnoses an abnormality in the axis mechanism as an abnormality of a nut portion or a rolling body of the ball screw, and
when the stroke position as the apex of the second-order approximation formula is on an opposite side of the coupling relative to the center of the stroke, the diagnosis unit diagnoses an abnormality in the feed axis mechanism as an abnormality of the coupling.