CALCULATORS / BEARINGS AND LINEAR GUIDES

Bearing friction and heat calculator

Supplied effective friction coefficient; no seal or lubricant model.

bearings-friction-torque.napkin / editable

SCENARIO COMPARISON

Compare the numbers.

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

Scenario	torqueN*m	lossW
	0.01	1.5708
	0.008	1.25664

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.

loss budget1.57 W✓ passes

BASELINE INPUTS

load500 Ndiameter20 mmcoefficient0.002 speed1500 rpm

CALCULATED

torque0.01 N*m

loss1.5708 W

Edits change the baseline source.

THE SOURCE

Edits below update the same model.

# Bearing friction and heat
# Scope: Supplied effective friction coefficient; no seal or lubricant model.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

load = 500 N
diameter = 20 mm
coefficient = 0.002
speed = 1500 rpm

torque := coefficient*load*diameter/2 [N*m]
loss := torque*speed [W]

check loss budget: loss <= 5 W

scenario alternative: load = 400 N

Calculated from your source · not saved

Baseline · Baseline

loss budget1.57 W ✓ passes

alternative · alternative

loss budget1.26 W ✓ 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.

torque: torque = coefficient*load*diameter/2 [N*m]
loss: loss = torque*speed [W]

Original worked example

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

Given

load: 500 N
diameter: 20 mm
coefficient: 0.002
speed: 1500 rpm

Calculated

torque: 0.01 N*m
loss: 1.5708 W

Assumptions and limits

Supplied effective friction coefficient; no seal or lubricant model.

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 friction and heat. Inputs: load; speed; selected friction model. Outputs: drag torque; loss power. 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: load, speed, selected friction model
Outputs: drag torque, loss power
Modes: calculate, compare, sweep
Drawing: Bearing load diagram

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