CALCULATORS / BEARINGS AND LINEAR GUIDES

Ball bearing L10 life calculator

Basic L10 ball-bearing life; no reliability or contamination modifiers.

bearings-rating-life.napkin / editable

SCENARIO COMPARISON

Compare the numbers.

This source describes an analytical model. Its quantities and checks are the view.

Scenario	millionRevolutions	periods	revolutionRates^-1	lifeh
	1000	0.04	25	11111.1
	512	0.04	25	5688.89

All calculated quantities are listed with the inputs. Switch to Source to inspect the equations.

SCENARIOS / CALCULATED VALUESSAME SOURCE

Change an input to see the consequences.

life target11111.11 h✓ passes

BASELINE INPUTS

rating5000 Nload500 Nspeed1500 rpm

CALCULATED

millionRevolutions1000

period0.04 s

revolutionRate25 s^-1

life11111 h

Edits change the baseline source.

THE SOURCE

Edits below update the same model.

# Bearing L10 rating life
# Scope: Basic L10 ball-bearing life; no reliability or contamination modifiers.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

rating = 5000 N
load = 500 N
speed = 1500 rpm

millionRevolutions := (rating/load)^3
period := 2*pi/speed [s]
revolutionRate := 1/period [s^-1]
life := millionRevolutions*1000000/revolutionRate [h]

check life target: life >= 5000 h

scenario alternative: rating = 4000 N

Calculated from your source · not saved

Baseline · Baseline

life target11111.11 h ✓ passes

alternative · alternative

life target5688.89 h ✓ passes

Illustrative first-order example. Checks are editable requirements, not design standards. The broader topic may require additional equations, data, and validation.

Formula and units

This example uses the following equations. Input names and units match the editable source above.

million revolutions: millionRevolutions = (rating/load)^3
period: period = 2*pi/speed [s]
revolution rate: revolutionRate = 1/period [s^-1]
life: life = millionRevolutions*1000000/revolutionRate [h]

Original worked example

These are the baseline values in the downloadable source. Edits above let you test your own values.

Given

rating: 5000 N
load: 500 N
speed: 1500 rpm

Calculated

million revolutions: 1000
period: 0.04 s
revolution rate: 25 s^-1
life: 11111.1 h

Assumptions and limits

Basic L10 ball-bearing life; no reliability or contamination modifiers.

The requirement checks use the limits written in this example. Passing a check does not establish that the model covers every load, material behavior, or operating condition in a real design.

Download this .napkin example ↓

Take it further with your agent

Napkin keeps the inputs, equations, checks and assumptions together in one study. Your agent sets it up; you change the numbers.

Try with Claude ↗

codex 'Use Napkin (https://napkin.engineering/mcp, or the local Napkin plugin) to build a study: Bearing L10 rating life. Inputs: dynamic capacity; equivalent load; speed; bearing type. Outputs: rating life in revolutions and hours. Model scope: Catalog-dependent load and statistical rating-life models. Read napkin_capabilities and the current snapshot. Ask me for the values that matter, label assumptions with units, author .napkin source, validate it and apply it with napkin_source using the current revision, then open the study. Add checks for the limits I supply. Keep unsupported analyses explicit.'

Claude needs the Napkin connector; Codex needs the Napkin plugin. Set up your agent ↗

The broader study

The topic brief below describes the broader scope. The worked example above states the particular calculation it implements.

Inputs: dynamic capacity, equivalent load, speed, bearing type
Outputs: rating life in revolutions and hours
Modes: calculate, compare, sweep
Drawing: Bearing load diagram

EXECUTABLE WORKED EXAMPLE · FIRST-ORDER MODEL · CHECK THE SCOPE & ASSUMPTIONS