The issues identified in this case study include a high 1X RPM which would be related to the misalignment found across the drive shaft from the motor to the gearbox. The peaks on either side of line frequency are at the output speed of the gearbox and the red arrows are indicators of blade issues. An investigation identified that the hub was eroded and the blades were loose as a result. The gear frequencies identified excessively worn gears in the gearbox, which was replaced. Items discussed: depth of testing, motor database, signatures, torsional analysis, and power quality.
20181125 Cooling Tower Motor Gearbox Blades and Power Quality Detection Using EMPATH Case Study