Cone-joint friction torque

What does this quantity describe?

At the mean cone circumference, normal force and static friction create FR=FNμ and therefore T=FNμDmF/2.

Formula and variables

T = FN·μ·DmF/2

• T = FN μ DmF / 2

Choose the inputs correctly

FN is the resultant normal to the cone surface, μ the static coefficient against slip and DmF the mean of large and small joint diameter.

How to use the calculator

Select the target, enter all remaining quantities for the actual component, and verify the units. Then compare the result with the stated model limits and with the required strength, safety and operating checks.

Worked example

20 kN, μ=0.1 and 250 mm give an ideal 250 N·m.

Understand the result and units

The result is ideal friction capacity before friction safety; it is not the required axial pressing force from equation 10.29.

The calculator converts internally to coherent SI units. Length, force, torque, stress and angle may therefore use the offered units; dimensionless factors are entered as decimals.

What is taken from Roloff/Matek

Only the closed-form relationship from Kapitel 12.3.2, Herleitung vor Gleichung (12.29) is used. Tabulated data, material limits and detailed design checks are not silently added; they remain explicit inputs or are expressly outside the model.

Typical applications

Cone-joint friction torque supports option comparison, plausibility checks and early sizing within its machine-element cluster. Releasing a design requires the additional checks described in the cited chapter.

Assumptions, limits and common mistakes

Ideal equal cone angles without manufacturing deviation or speed effects; determine push-on distance, pressure, axial force and friction safety separately.

Common mistake: Typical errors are misreading the effective length or force, entering percentages instead of decimals, and treating a preliminary result as a complete verification. In particular: Ideal equal cone angles without manufacturing deviation or speed effects; determine push-on distance, pressure, axial force and friction safety separately.