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Torque Formula:
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Torque is the rotational force produced by an electric motor. It's a crucial parameter that determines the motor's ability to perform work and overcome resistance. Torque is typically measured in Newton-meters (Nm) in the metric system.
The calculator uses the torque formula:
Where:
Explanation: The formula shows that torque is inversely proportional to speed - motors running at lower RPMs produce more torque for the same power input.
Details: Knowing a motor's torque is essential for proper motor selection, ensuring it can handle the required mechanical load. It's critical in applications like conveyor systems, pumps, and machine tools where starting and running torque requirements differ.
Tips: Enter the motor's rated power in kW and its operating speed in RPM. The calculator will compute the torque in Nm. Both values must be positive numbers.
Q1: What's the difference between starting and running torque?
A: Starting torque is the torque when the motor begins turning from rest, typically higher than running torque which is the torque during normal operation.
Q2: How does voltage affect torque?
A: For AC induction motors, torque is proportional to the square of the voltage. A 10% voltage drop results in about 19% torque reduction.
Q3: What is the relationship between torque and horsepower?
A: Horsepower = (Torque × RPM)/5252 (in US units). They're related through rotational speed - at 5252 RPM, torque (lb-ft) and horsepower are equal numerically.
Q4: Why does torque decrease as speed increases?
A: For a given power, torque must decrease as speed increases because power is the product of torque and angular velocity (P = τ × ω).
Q5: How do I select a motor based on torque requirements?
A: Choose a motor whose torque-speed curve exceeds your application's requirements, considering both starting and running conditions with appropriate safety margins.