Torque is the turning force through a radius – with the units Nm in the SI-system and the units lb ft in the imperial system. The torque developed by an asynchronous induction motor varies when the motor accelerates from zero to maximum operating speed.
What gives an electric motor torque?
Electric motors operate on three different physical principles: magnetism, electrostatics and piezoelectricity. In magnetic motors, magnetic fields are formed in both the rotor and the stator. The product between these two fields gives rise to a force, and thus a torque on the motor shaft.
What determines the torque of a motor?
Divide the number of watts by 746 to get the horse power rating of the electrical motor. … Multiply the horsepower by 5,252 using a calculator. Using the example figure, multiply 0.6434316 by 5,252 to get 3,379.3027. Divide the answer by the motor’s rated number of rpm to get the measurement of the torque in pound-feet.
What determines the torque of a DC motor?
1 Answer. Torque of a motor is directly proportional to current. Therefore, the maximum torque a motor can produce is limited by the maximum current it can handle. The maximum steady state current a motor can handle is limited by the heat it can safely dissipate, which is proportional to the square of the current.
Why do electric motors have so much torque?
The benefit of using an electric motor to power a car is that it can help drivers reach maximum torque from 0 RPM. This is because electric motors use an electric current, which moves through a magnetic field and creates the force necessary to rotate the armature and get the car moving.
Why do electric motors lose torque at high rpm?
Because doing so would compromise efficiency and drivability. As engine speed increases, so does it’s inefficiency. Higher RPMs cause more wear, and waste more fuel. For that reason, vehicles usually cruise at a engine speed much below the point where they make maximum power.
How do you increase torque in a motor?
If you want to adjust the output torque within the rated torque range, you can usually adjust the input voltage or the amount of excitation current. If the DC motor has been set, the torque can only be increased by the speed reducer, which can be multiplied or even increased by a thousand times.
Do electric motors have constant torque?
When you think about what an electric motor is, the answer is fairly simply, it’s an object that changes electrical energy in to mechanical energy. … In the case of our motors, torque is a turning force that produces rotation of the output shaft. DC motors can develop a constant torque over a wide speed range.
How do I calculate torque?
A practical way to calculate the magnitude of the torque is to first determine the lever arm and then multiply it times the applied force. The lever arm is the perpendicular distance from the axis of rotation to the line of action of the force. and the magnitude of the torque is τ = N m.
Is it better to have more torque or less torque?
Of course, horsepower is tied to torque mathematically. … Because there is generally a limit on how fast you can spin an engine, having higher torque allows for greater horsepower at lower rpms. This is also why people talk about “low-end torque” being important for better power at slower speeds.
Which is proportional to the torque in dc motor?
For a particular DC Motor, the number of poles (P) and the number of conductors per parallel path (Z/A) are constant. Thus, from the above equation (5) it is clear that the torque produced in the armature is directly proportional to the flux per pole and the armature current.
What is the relationship between torque and speed?
Torque is inversely proportional to speed. Thus, when speed increases, torque will decrease.
Why do diesels have more torque?
Why torque is increased in diesel engines
Diesel engines are designed with longer strokes in mind, as this produces more torque and more power. The more pressure built in the strokes and cylinders, the more torque the wheels will have. The combustion temperature of diesel fuel is also designed for higher torque.
How much torque does a 1 hp motor have?
The 1800 RPM, 1HP motor produces 3 ft. lbs of torque at 1800 RPM. The 3600 RPM, 1HP motor produces 1.5 ft.
What creates more torque?
The amount of torque produced is directly proportional to the air flowing through the engine. Large engines pump more air and, therefore, produce more torque.