Ball screw preload loss detection using ball pass frequency

• We propose a method to detect the preload loss in a ball screw feed drive system.
• The onset of preload loss is detected by monitoring the ball pass frequency (BPF).
• BPF is measured by Angular Velocity Vold–Kalman Filtering Order Tracking (AV VKF-OT).
• Ball screws with different preloads were tested for assessment of proposed method.

A technique of determining the onset of preload loss in a ball screw feed drive system via monitoring the change of ball pass frequency is proposed. The ball pass frequency of a ball screw with preload is smaller than that of ball screw without preload due to friction caused by the preload. Results from both simulations and experiments show that the ball pass frequency can be detected using the method of Angular Velocity Vold–Kalman Filtering Order Tracking (AV VKF-OT). And AV VKF-OT provides a much better performance as compared to the traditional order tracking in terms of resolution and accuracy. Tests were conducted on ball screw feed drive systems with different preloads for the performance assessment of the ball pass frequency detection. Results show that the preload loss increases the ball pass frequency and also induces the side band around the ball pass frequency, which provides promising criteria in detecting the onset of preload loss of ball screws.