Axial rating-life arithmetic
Ball-screw nominal life
Inputs
User-entered basic axial dynamic load rating for one identified ball screw.
User-entered constant axial load in the stated direction; equivalent load is not derived.
User-entered linear travel per revolution for the stated ball screw.
User-entered rotating speed used only for literal time conversion.
Percent of elapsed time at the declared rotating travel condition, from greater than 0 through 100.
Results
Nominal life
27,000,000
Ideal travel distance
270
Literal rotating time
375
Literal elapsed time at declared travel fraction
937.5
Declared dynamic-rating / axial-load ratio
3
—L10 = (Ca/Fa)³·10⁶ rev; s = L10·Ph; telapsed = L10/[60n·ftravel]
A first-pass number, not a code check, certification, or approval. Read the method and its limits below. What this is and is not.
Nearby: Axial response · Beam deflection & reactions · Elastic stability · Solid-shaft torsion
Method
Formula, when it applies, and when it does not
Calculate nominal ball-screw revolutions, ideal travel distance, and stated-duty operating time from axial rating, load, lead, speed, and travel fraction.
L10 = (Ca/Fa)³·10⁶ rev; s = L10·Ph; telapsed = L10/[60n·ftravel]
When
- Constant axial load direction and magnitude
- User-entered axial dynamic rating
- Declared lead and rotational speed
- Stated travel fraction
Don’t
- This applies the cited constant-direction axial ball-screw nominal-life relation using user-entered dynamic rating and axial load, then makes ideal lead/speed/travel-fraction conversions. It does not derive equivalent loads, model shocks, vibration, fluctuating duty, mounting, lubrication, alignment, preload, screw/nut selection, safety, suitability, or approval.