Use this torque loss calculator to find the difference between armature torque and shaft torque. It can also calculate shaft torque or armature torque using reversible motor torque loss formulas.
Assumptions & Formulas
– Torque Loss = Armature Torque − Shaft Torque
– Shaft Torque = Armature Torque − Torque Loss
– Armature Torque = Shaft Torque + Torque Loss
Definitions:
– Armature Torque (Gross): The total torque developed by the motor armature electromagnetically.
– Shaft Torque (Net): The actual, useful torque available at the motor shaft for doing work.
– Torque Loss: The difference between armature and shaft torque, caused by mechanical friction, windage, and iron losses.
Note: Armature Torque must always be greater than or equal to Shaft Torque. Results are mathematically rounded to 2 decimal places.
This torque loss calculator determines the exact difference between motor armature torque and shaft torque. By providing your known values, you can instantly find the missing variable using the core formula: $$Torque Loss = Armature Torque – Shaft Torque$$. The tool is fully reversible, meaning you can easily switch modes to calculate either the shaft torque or the armature torque when the amount of torque loss is already known.
Please note that this tool is designed exclusively for engineering applications to measure motor torque loss, represented here as the difference between gross armature torque and net shaft torque, including losses such as friction, windage, and iron losses. It is not an orthodontic torque-loss calculator, even though search results for this exact term sometimes mix dental and engineering intents.
Torque Loss Formula
Depending on the calculation mode you select, the tool applies one of the following three formulas:$$Torque Loss = Armature Torque – Shaft Torque$$$$Shaft Torque = Armature Torque – Torque Loss$$$$Armature Torque = Shaft Torque + Torque Loss$$
What to Enter
To get an accurate result, provide two known values based on your selected calculation mode:
- Torque Loss mode: Enter the Armature Torque and the Shaft Torque.
- Shaft Torque mode: Enter the Armature Torque and the Torque Loss.
- Armature Torque mode: Enter the Shaft Torque and the Torque Loss.
You can input each torque value in Newton-meters (Nm), pound-feet (lb-ft), or kilogram-meters (kg-m).
What the Calculator Returns
The tool will return one single missing value based on your selected mode:
- Calculated Torque Loss
- Calculated Shaft Torque (Net)
- Calculated Armature Torque (Gross)
You can change the unit of your final result independently to Nm, lb-ft, or kg-m after the calculator normalizes the entered values to Nm and computes the result.
Torque Units Supported
| Unit | Used for inputs | Used for outputs |
|---|---|---|
| Newton-meters (Nm) | Yes | Yes |
| Pound-feet (lb-ft) | Yes | Yes |
| Kilogram-meters (kg-m) | Yes | Yes |
Unit Conversion Logic Used by This Calculator
To ensure accurate math across different measurement systems, the calculator first normalizes all entered values to Newton-meters (Nm). After performing the subtraction or addition, it converts the final result from Nm into your chosen output unit.
| Conversion path in tool | Formula |
|---|---|
| lb-ft → Nm | $$Nm = lb-ft \times 1.35581795$$ |
| kg-m → Nm | $$Nm = kg-m \times 9.80665$$ |
| Nm → lb-ft | $$lb-ft = Nm / 1.35581795$$ |
| Nm → kg-m | $$kg-m = Nm / 9.80665$$ |
Calculation Modes in This Torque Loss Calculator
You can switch between three functional modes using the selector in the tool:
- Torque Loss mode: Calculates the loss directly from a known armature torque and shaft torque.
- Shaft Torque (Net) mode: Calculates the final shaft torque by subtracting the torque loss from the armature torque.
- Armature Torque (Gross) mode: Calculates the initial armature torque by adding the shaft torque and the torque loss together.
Assumptions Used
The calculator relies on a few mechanical rules to process your numbers:
- Armature torque must always be greater than or equal to shaft torque.
- Torque loss cannot be a negative number.
- Final results are automatically rounded to 2 decimal places.
- The tool treats torque loss strictly as the difference between gross armature torque and net shaft torque caused by physical realities like friction, windage, and iron losses.
Limits of This Calculator
To use this tool effectively, please keep the following boundaries in mind:
- It calculates the raw torque difference, not the efficiency percentage.
- It does not calculate torque from power, RPM, force, radius, or drivetrain gearing.
- It does not model variable loss curves across different speeds, loads, temperatures, or transmission conditions.
- It is strictly a direct subtraction and addition tool based entirely on armature torque, shaft torque, and torque loss.
Example Uses of the Calculator
This tool is built to handle three specific scenarios:
- Find the torque loss when the gross motor torque and the net shaft torque are known.
- Find the shaft torque after a known torque loss is subtracted from the armature torque.
- Find the required armature torque when a needed shaft torque and an expected torque loss are both known.
FAQ
What is torque loss?
In the context of this calculator, torque loss is simply the difference between armature torque and shaft torque. It is calculated exactly as: $Torque Loss = Armature Torque – Shaft Torque$.
What formula does this torque loss calculator use?
It uses the standard relationship: $Torque Loss = Armature Torque – Shaft Torque$. It also rearranges that exact same math to solve for either shaft torque or armature torque.
Can I calculate shaft torque with this tool?
Yes. When you select the Shaft Torque (Net) mode, the calculator uses the formula: $Shaft Torque = Armature Torque – Torque Loss$.
Can I calculate armature torque with this tool?
Yes. When you select the Armature Torque (Gross) mode, the calculator uses the formula: $Armature Torque = Shaft Torque + Torque Loss$.
What units can I use?
You can enter your initial values and return your final results in Nm, lb-ft, and kg-m.
Why does the calculator reject shaft torque greater than armature torque?
The tool assumes torque loss is a non-negative difference between the gross armature torque and the net shaft torque. Because of this, the shaft torque cannot physically exceed the armature torque inside this specific model.
Is this the same as an orthodontic torque loss calculator?
No. While search results for this exact keyword are mixed, this tool is strictly the engineering version based on motor armature torque and shaft torque.
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