Case Study: Bearings
A major salad dressing maker in Toronto put the UL101 to test. Two other competitive products were also tested in the same setting. A motor was used in conjunction with a gearbox and metal chain to drive a conveyor where the salad dressing bottles were moved down the line. A maintenance expert had already suspected that the motor was ready to fail but had no means of distinguishing between motor noises and gearbox noises.
The competitive ultrasonic sensors were unable to distinguish the sounds of the gearbox and motor bearings because of the ambient ultrasound created by glass bottles moving down the conveyor, the metal chain, and a metal guard that was loose. Testing with the UL101 in contact mode eliminated all of the ambient ultrasound. While starting at a point of contact on the gearbox housing closest to the conveyor, the UL101 was contacted at different locations along the gearbox and motor. SoundCTRL was used in conjunction with the UL101 to take recordings of the results (Listen to the results below).
A distinct low humming sound could be heard all along the shaft and grew in intensity as the UL101 moved further away from the conveyor and towards the front end of the motor. The motor was taken offline and hand turned to see if there was a bearing problem. The mechanics suggested that the bearings were fine. When the motor was placed back on line, but disconnected from the gearbox, the loud sound still occurred above the front-end bearing. The fan was removed and the bearing cover was then opened for visual inspection to reveal that the bearing was completely rusted. A new bearing could be ordered for $100. The UL101 immediately saved money. A new motor would cost $1300, but savings also considered would include potential lost production and time to replace.
1st point of contact - Gearbox | SoundCTRL - Flash (157k)