How to use a torque-speed curve to select a servo motor?

 

A torque-speed curve represents the relationship between the motor's torque output and its rotational speed. It provides valuable insights into the motor's performance characteristics, helping you determine its suitability for specific applications. Typically, the curve shows the motor's maximum continuous torque, maximum intermittent torque, and the speed range over which these torques can be delivered.

 

 

 

 

 

 

Picture from: ISS23-10

 

 

 

 

 

 

 

 

 

 

 

 

Step 1: Determine Application Requirements:

Before using a torque-speed curve, you need to identify the specific requirements of your application. Consider factors such as the required torque, speed range, acceleration/deceleration rates, and any intermittent or peak load conditions that may arise. These requirements will serve as the basis for selecting an appropriate servo motor.

 

 

 

 

 

 

Picture from: ISV57T-090

 

 

 

 

 

 

 

 

 

 

 

Step 2: Obtain the Torque-Speed Curve:

Consult the manufacturer's documentation or datasheet to obtain the torque-speed curve for the servo motor models you are considering. The torque-speed curve typically illustrates the motor's torque output in relation to its rotational speed, expressed in terms of percentage or ratio.

 

Step 3: Analyze the Torque-Speed Curve:

Examine the torque-speed curve and identify the motor's continuous torque rating. This represents the maximum torque the motor can deliver continuously without overheating. Ensure that your application's required torque falls within this range.

 

Next, consider any intermittent or peak torque requirements. The torque-speed curve may also indicate the maximum intermittent torque the motor can deliver for a limited duration. Make sure your application's peak torque demands can be accommodated by the servo motor.

 

Evaluate the speed range over which the motor can deliver the required torque. Ensure that the motor's operational speed range aligns with your application's speed requirements. Consider the motor's ability to handle acceleration and deceleration rates, as these affect the dynamic performance of the system.

 

Step 4: Compare and Select:

Compare the torque-speed curves of different servo motor models and assess their suitability based on your application requirements. Choose a servo motor that provides adequate continuous and intermittent torque, operates within the required speed range, and meets any other specific demands of your application.