CVA Bearing Analysis & Fault Detection

Question 1

What are the four fundamental bearing defect frequencies for a rolling element bearing?

Accepted Answer

BPFO, BPFI, BSF, FTF

Answer

1×, 2×, 3×, 4×

Answer

GMF, BSF, FTF, RPM

Answer

NF, FF, SF, BF

Question 2

Which bearing defect frequency is typically the lowest and corresponds to cage rotation?

Accepted Answer

FTF

Answer

BPFO

Answer

BPFI

Answer

BSF

Question 3

In the early stages of rolling element bearing failure, defect-related energy typically appears first in which frequency range?

Accepted Answer

Ultrasonic frequencies (20 kHz and above), then high-frequency resonances

Answer

Sub-synchronous (below 1× running speed)

Answer

1× to 3× running speed range

Answer

At the exact bearing defect frequency in the low-frequency spectrum

Question 4

What is the envelope (demodulation) technique used for in bearing analysis?

Accepted Answer

Detecting the repetitive impact pattern of a bearing defect by bandpass filtering and demodulating a high-frequency resonance

Answer

Removing electrical noise from proximity probe signals

Answer

Integrating acceleration to velocity for low-frequency analysis

Answer

Measuring bearing clearance by shaft orbit analysis

Question 5

What does BPFO stand for, and what does it represent?

Accepted Answer

Ball Pass Frequency Outer race; the rate at which rolling elements pass a defect on the outer race

Answer

Bearing Peak Force Output; the maximum load a bearing can sustain

Answer

Bearing Pre-load Force Offset; the axial preload applied to angular contact bearings

Answer

Base Point Frequency Oscillation; the resonant frequency of the bearing housing

Question 6

Which parameter is used in high-frequency bearing diagnostics to quantify the overall impulsiveness of the bearing signal?

Accepted Answer

Kurtosis

Answer

RMS velocity

Answer

Peak displacement

Answer

Crest factor only