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.
Do electric motors have torque?
The driving force of an electric motor is torque – not horsepower. The torque is the twisting force that makes the motor running and the torque is active from 0% to 100% operating speed. Note! – the full torque from zero speed is a major advantage for electric vehicles.
What determines the torque of an electric motor?
Electrical energy, measured in watts, can be used to produce torque, and an electric motor is a good example of electrical energy that can produce torque. … Divide the number of watts by 746 to get the horse power rating of the electrical motor.
What is a constant torque motor?
Constant torque motors are high-efficiency, brushless DC motors that are based on the same ECM technology described in ECM 2.3 variable-speed motors. … In other words, if the ESP changes, then the motor program will maintain the amount of torque for which it was programmed (this is not the same as constant airflow).
What is constant torque?
CONSTANT TORQUE LOADS. With constant torque loads, the torque loading is not a function of speed. Typical applications are: Traction drives, Compressors, Conveyors, Positive displacement pumps, Mixers and Hoists. As the speed changes, the load torque remains constant and the horsepower changes linearly with speed.
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.
Why do electric cars produce more 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?
Nearly half of electrical failures in motors begin with weakening of the insulation around individual wires in the motor coils. This is often caused by thermal stress, contamination and movement of the winding due to the magnetic forces during start-up and shut-down of the motor.
Does more torque mean faster acceleration?
Basically, the faster the crankshaft spins with the same amount of force, the more power an engine will make. A car with more hp than torque will always be quicker since this gives a car acceleration and speed. … Higher torque doesn’t mean one vehicle will necessarily be faster than another, though.
Are ECM motors quieter?
ECM motors are very high efficiency (65% to 80%) electric motors. … ECM motors are also quieter than traditional inefficient motors, have longer design life and require less maintenance.
Are DC motors constant torque?
DC motors can develop a constant torque over a wide speed range. For a DC motor : Torque is proportional to armature current – this means controlling torque requires simply controlling the motor DC current – easily achieved with a simple DC drive.
What is the difference between an ECM motor and a variable speed motor?
Both variable speed and X13 motors are ECM or “Electronically Commutated Motors,” This means the DC power that drives them is electronically switched from positive to negative to spin the motor. … The primary difference is the type of inputs to the motor control.
How do you increase torque in a VFD?
Since a VFD cannot increase the voltage above its supply voltage, the current decreases as frequency increases, decreasing the available torque. Theoretically, torque is reduced by the ratio of the base speed to the higher speed (60 hertz / 90 hertz = 67 percent).
Is a fan constant torque or variable torque?
Variable torque loads include centrifugal pumps, fans, and blowers. The faster the motor spins, the more current it draws from the VFD to deliver the demanded torque.
How do you calculate torque constant?
The Torque Constant defines the torque-current relationship of a motor and is in Nm/amp. The motor and torque constants are related by the formula Km = Kt(trap)/sqrt(R), where R is the phase-to-phase resistance of the winding.