Calculation
P = F·v / η
Mechanical power is the product of force and velocity; drivetrain losses raise the electrical power that must actually be supplied.
Dubbel Kraftfahrzeugtechnik Q 2.1: PW = FW·v, Antriebsverluste über η = η1·η2·…·ηn (Q 2.1.3); P = F·v/η
Drive power from force, velocity and efficiency
Mechanical power is the product of force and velocity; drivetrain losses raise the electrical power that must actually be supplied.
MINTSI
02
Result
Select a target and calculate.
Understand the inputs
- Required drive power P — Power to be supplied at the drive, including losses between drive and point of force application.
- Feed force F — Constant force in the direction of motion at the considered speed.
- Velocity v — Constant velocity in the direction of the force.
- Efficiency η — Overall efficiency between electrical drive and mechanical force transmission.
Example
F=500 N, v=1.5 m/s and η=0.85 give P=500·1.5/0.85≈882.4 W.
Assumptions and limits
Steady, straight-line motion with constant force, velocity and efficiency; acceleration power and dynamic load peaks are excluded.
Understand Drive power from force, velocity and efficiency
This calculator determines the power a drive must actually supply for straight-line motion, accounting for transmission losses.
What does this quantity describe?
Mechanical power is the product of force and velocity, Pmech=F·v. Drivetrain losses are captured via efficiency η: P=Pmech/η.
Formula and variables
P = F·v / η
Pmech = F·vP = Pmech/η
| Symbol / input | Meaning |
|---|---|
| Required drive power P | Power to be supplied at the drive, including losses between drive and point of force application. |
| Feed force F | Constant force in the direction of motion at the considered speed. |
| Velocity v | Constant velocity in the direction of the force. |
| Efficiency η | Overall efficiency between electrical drive and mechanical force transmission. |
Choose the inputs correctly
F is the force acting in the direction of motion, v the velocity in the same direction, and η the overall efficiency of the force transmission.
How to use the calculator
Take F and v from the application's load analysis; take η from manufacturer data for a gearbox, screw drive or belt drive.
Worked example
F=500 N, v=1.5 m/s and η=0.85 give P=500·1.5/0.85≈882.4 W.
Understand the result and units
Lower efficiency raises required drive power disproportionately relative to the visible mechanical losses.
F is a force, v a velocity and η dimensionless. P is output as a power.
Typical applications
Basic sizing of linear actuators, hoists, conveyors and other applications with straight-line force transmission.
Assumptions, limits and common mistakes
Steady, straight-line motion with constant force, velocity and efficiency; acceleration power, static friction and dynamic load peaks are excluded.
Common mistake: Do not enter η>1; an efficiency is always less than or at most equal to 1.
Frequently asked questions
What is “Drive power from force, velocity and efficiency” used for?
Basic sizing of linear actuators, hoists, conveyors and other applications with straight-line force transmission.
Where do the input values come from?
F is the force acting in the direction of motion, v the velocity in the same direction, and η the overall efficiency of the force transmission.
What does the result not cover?
Steady, straight-line motion with constant force, velocity and efficiency; acceleration power, static friction and dynamic load peaks are excluded.