calculate_bearing_characteristic_frequencies
Calculate bearing fault frequencies (BPFO, BPFI, BSF, FTF) from geometry and speed to diagnose rolling-element bearing issues.
Instructions
Calculate bearing characteristic frequencies from geometry.
Standard rolling-element kinematic formulas (Randall & Antoni 2011,
"Rolling element bearing diagnostics — A tutorial", MSSP 25(2)).
Requires the EXACT geometry — from the manual, the catalog
(search_bearing_catalog), or the user; never guessed. Deep-groove
ball bearings have contact_angle_deg = 0.
Args:
num_balls: Number of rolling elements (Z)
ball_diameter_mm: Ball/roller diameter (Bd) in mm
pitch_diameter_mm: Pitch circle diameter (Pd) in mm
contact_angle_deg: Contact angle (alpha) in degrees
rpm: Shaft rotation speed in RPM
ctx: MCP context. Unused — see this module's docstring on logging.
Returns:
Dictionary with BPFO, BPFI, BSF, FTF in Hz.
Example:
>>> # 6205 geometry (CWRU Bearing Data Center) at 1797 RPM
>>> freqs = calculate_bearing_characteristic_frequencies(
... num_balls=9, ball_diameter_mm=7.94,
... pitch_diameter_mm=39.04, rpm=1797
... )
>>> round(freqs['BPFO'], 2)
107.36
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| rpm | No | ||
| num_balls | Yes | ||
| ball_diameter_mm | Yes | ||
| contact_angle_deg | No | ||
| pitch_diameter_mm | Yes |
Output Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||