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.

The content & opinions in this article are the author’s and do not necessarily represent the views of RoboticsTomorrow

Servo2Go.com Ltd.

Servo2Go.com is an Online E-Store Distributor of Automation & Motion Control Systems & Components including: Servo Motors & Drives, Stepper Motors & Drives, Automation & Motion Controllers, Positioning Systems & Actuators, Gearboxes, Couplings, Brakes, Encoders, Tachometers, Linear Displacement Transducers, HMI's, PLC's and Embedded Controllers. Servo2Go.com is an ISO9001:2008 Registered Company.

Other Articles

Optimizing Servo System Performance: A Comprehensive Guide to Eliminating Electrical Noise and Enhancing Noise Immunity

This whitepaper will delve into the steps and techniques necessary for mitigating electrical noise in servo systems, ensuring optimal performance and reliability for high-precision applications.

Understanding the Motor Constant in DC Motor Sizing

One of the most often overlooked parameters of direct current motors (both brush and brushless) is the Km or motor constant. The motor constant (expressed as Km) defines the ability of a motor to transform electrical power into mechanical power.

Understanding Torque Ripple in Servo Motors

Torque ripple must be defined as a function of output load and speed. For load specification the most sensible rating point is the continuous duty thermal torque rating for the servo motor.

More about Servo2Go.com Ltd.

Featured Product

ATI Industrial Automation - MC-50 Manual Tool Changer

With intuitive and ergonomic lever operation, the patent-pending MC-50 Manual Robot Tool Changer provides a simple solution for quickly changing robotic end-of-arm tooling by hand. This compact and robust Tool Changer is designed for applications on collaborative robots that support payloads up to 25 kg and small industrial robots supporting payloads up to 10 kg. Featuring an ISO 50 mm mounting interface on the Master-side and Tool-side, the low-profile MC-50 mounts directly to most cobots and seamlessly integrates with many common cobot marketplace grippers and end-effectors.

More Products

Feature Your Product