Electric Motor Rpm Torque Curve

Reciprocating steam engines and electric motors can start heavy loads from zero rpm without a clutch.

Electric motor rpm torque curve. As a current flows through the electric motor a related electrical charge causes an armature to rotate. Speed torque gradient. Other electric motors may in fact produce maximum torque throughout their entire operating range. P hp horsepower delivered by the electric motor hp.

The torque speed curves shown below are actual curves for the green maxon motor pictured at right used by students in 2 007. This is the opposite coefficient of the linear speed torque curve. T inlb torque in lb f. T inlb p hp 63025 n 1.

Steam engines and electric motors tend to produce maximum torque close to zero rpm with the torque diminishing as rotational speed rises due to increasing friction and other constraints. For example the ac motor found in the tesla roadster 2008 produces near constant maximum torque from 0 to about 6000 rpm while maximum power occurs at about 10000 rpm long after torque begins to drop off. Relationship between torque power and energy. The speed torque curve is expressed by the following equation n as speed t as torque.

The roadster s redline is 14000 rpm. Motor torque speed curve is a very good approximation. Usually in rpm v. The linear model of a d c.

By overlaying the torque speed curve of a pump and a motor one can verify that the motor is producing enough accelerating torque to drive the pump to full speed as shown below. 1 ft lb f 1 356 nm. T ftlb torque lb f ft. That is why the shaft and frame of a 900 rpm motor are usually larger than those of an 1 800 rpm motor of the same hp.

N revolution per minute rpm alternatively. Figure 1 provides a graphical illustration of these changes. Thankfully in electric motors maximum torque is produced from the get go. T ftlb p hp 5252 n 1b.

Like pumps motors produce a torque speed curve of their own. Introduction of a vfd when the speed of an ac motor is controlled by a vfd hp or torque will change depending on the change in frequency. One is a plot of empirical data and the other was plotted mechanically using a device developed at mit.