The importance of the Speed-Torque Gradient in DC Motor Sizing

March 29, 2019

By: Warren Osak, CEO/Founder of Electromate

Often overlooked when sizing DC motors is the Speed-Torque Gradient.

The Speed-Torque Gradient is defined as  Δn / ΔM [rpm/mNm] .

The speed / torque gradient is an indicator of a motor’s performance. The smaller the value, the more powerful the motor and consequently the less motor speed varies with load variations. It is based on the quotient of ideal no-load speed and ideal stall torque.

The speed torque-gradient can be considered a measure of the motor strength, which is defined by motor type and size and not the winding selected. Basically it’s how much speed drop the motor will have for each 1mNm of torque applied.

In the figure above, enhancing the load torque leads to a linear reduction of the speed. Thus it becomes clear what the meaning of Δn/ΔM is: It’s the gradient of the speed-torque line.

Related Articles

Eaton

Eaton: Variable Frequency Drives Enhance Energy Efficiency at Greenhouse Waste Recycling Plant

 

In today’s market operational efficiency is essential. Whether it be upgrades to aging infrastructure or the application of new products into a modern facility there is a market wide drive to ensure that facilities are energy efficient and have proper control infrastructure. The push for efficiency has gone beyond the narrow consideration of manufacturing to incorporate a wide array of facilities that utilize modern machinery and control systems.

 

 

Brushed vs. Brushless DC Motors – What’s the Difference?

Brushed vs. Brushless DC Motors – What’s the Difference?

In the world of motors, efficiency is king. It is apparent that consumers are looking for not only efficiency in cost to operate but also in ability to get the task done quickly. When converting electricity into rotational motion via motors, a major contributing factor to efficiency is the type of motor, such as a DC motor, used to keep the momentum going.

 

 

 

| | | |

Revealing the Real Story Behind Motor Power and VFD Ratings: Avoid Costly Mistakes

October 15, 2024 Understanding Motor Power Rating and VFD Ratings: The Reality Behind Normal Duty and Heavy Duty Selections When it comes to selecting a VFD for a motor, many professionals start with the values provided for Normal Duty (ND) and Heavy Duty (HD). It seems straightforward — these ratings supposedly help match a drive…

Editor’s Pick: Featured Article

Weidmüller’s u-control 2000: The Automation Controller

Weidmüller’s u-control 2000: The Automation Controller

Weidmüller’s scalable engineering software, u-control 2000, adapts individually to your requirements. And, the u-control is powerful, compact and fully compatible with Weidmüller’s I/O system u-remote. This article looks at what makes u-control the heart of your automation.

Programmable logic controllers (PLCs) are one of the main components of any automated system. A typical control system has inputs, outputs, controllers (i.e., PLCs), and some type of human interaction with the system, a human machine interface (HMI), for example.

Read More

Latest Articles