Is failing bearing causing the vibration?
When machine vibration increases, one of the first questions asked is: "Is a failing bearing causing the vibration?" In the case of rolling element bearings, it is not difficult to separate vibration caused by a failing bearing from other common faults such as unbalance, misalignment, looseness, etc. But sorting out vibration from a failing rolling element bearing (here-after called "bearing vibration") from process sources such as flow induced and background vibration can be more demanding. The secret is to identify the frequency at which a flaw on a roller or raceway will impact the mating bearing component. These are commonly known as bearing fault frequencies. Topics covered include:
- Simple to complex steps in identifying bearing vibration
- "Locate rpm" function
- Occurance of sidebands