3-D Imaging Spindles For High Speed European Rail Inspection

ABTech designed a set of three high-speed air-bearing spindles which were synchronized for the 3-dimensional image scanning and inline inspection of the European high-speed rail system. These spindles are mounted on a dedicated rail car traveling at 75 mph creating a 3-D image every 10 cm   (less than 4″) of the rail to inspect the track, switches, tunnels, and bridges for potential maintenance issues.

This application-specific design incorporated individual direct drive brushless DC servo motors and encoders on each of the ultra-precision air-bearing spindles to achieve rotational speeds of 18,000 rpm. The spindles were put through various tests including, vibration testing up to 10 G’s, and being stored in a freezer overnight, and then run at 180°F continuously for over 8 hours to simulate the most extreme conditions.

Features of the Imaging Spindles:

  • Synchronized ultra-precision air bearing spindles
    • Aluminum construction for low inertia
    • Individual direct drive brushless DC servo motors
    • High-resolution rotary encoders
    • 50 mm clear apertures through the spindles
    • 45° fold mirrors
  • Vibration isolation platform
  • Multi-axis controller
  • Capacitance probe monitoring system