Torsional analysis is extremely important in determining the vibratory behavior of rotating systems such as engine driven pumps or generators.
Typically, torsionals have been measured at points along the system by looking at gear teeth (such as the flywheel ring gear) with a magnetic pick up. Points not having a production gear have been measured by either (1) fixing a machined gear to the shaft, or (2) mounting an encoder at the “end” of the system, or (3) utilizing a laser torsional vibrometer.
6D has developed a fourth option which utilizes wrapping magnetic tape around the circumference of a rotating part such as engine dampers or couplings. The tape has precisely spaced windows that allows a signal from a mag pickup to be similar to that from gear teeth.
6D’s torsional analysis software can accommodate the uneven spacing that occurs when the tape “meets itself” after one wrap around the component. The software also can adjust for different mean shaft speeds in the rotating system; useful when auxiliary components are driven through a gear box.
This system is a cost effective alternative to conventional methods for measuring torsional displacements and phase relationships by engine order of a rotating system.