What is the inertia of the servo motor? Worth collecting!
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Release time:
2024-10-29 17:05
Source:
In the selection video of the servo system in the last period, the word "inertia" has caused many partners to discuss. A small number of partners said that when choosing a servo motor, they often ignore it. Most partners question how to choose the inertia of servo motor?
So, now it might as well take two minutes to easily solve our "inertia confusion" from small cases in life ".
1. What is the inertia of a servo motor?
In daily life, it is not difficult to find that some things are easy to push, while others require a lot of effort.
For example, when pushing a stroller, you can push it with little effort. But it takes a lot of effort to push a bucket truck full of cement.
The different reaction speeds and force requirements that drive these two cars are actually "inertia" at work.
The inertia of the servo motor is a similar concept, which represents the sensitivity of the servo motor to acceleration or deceleration response.
It can be understood as the "degree of effort" required by the servo motor to start and stop ":
· The inertia is large, and the motor needs more strength to start;
· Small inertia, light starting strength and quick response.
In addition, the inertia of the servo motor generally includes the rotor inertia and the load inertia.
Rotor inertia is the inertia of the rotor within the motor, while load inertia is the inertia of the device or machinery driven by the motor.
Ideally, the ratio between the rotor inertia and the load inertia should be moderate. In other words, the ratio of rotor inertia to load inertia is infinitely close to 1:1, so that the servo motor performance can be more easily, efficiently and energy-saving.
⬆If the load inertia is too large, it is equivalent to letting the servo motor push the "full load truck", which will cause the response time of acceleration and deceleration to be slow, and may even cause the system to be unstable;
⬇If the load inertia is too small, the motion performance of the servo motor may not be effectively exerted, resulting in jitter dislocation.

So,In the practical application of servo motor, the importance of inertia lies in how to balance the response and stability of acceleration/deceleration.For example, the robot arm needs to be responsive when grasping items, while the injection molding manipulator needs more continuous power and stability, which is inseparable from the fine control of inertia.
2. Servo motor inertia is divided into several kinds?
According to different needs, the inertia of servo motors is divided into three categories: low inertia, medium inertia and high inertia.
low inertia servo motor
The low inertia servo motor is very sensitive, starting and stopping quickly, suitable for equipment that requires frequent and fast action.
For example, robot grippers quickly grasp items on the assembly line, and low-inertia motors can start and stop quickly to ensure work efficiency and accuracy.
Medium inertia servo motor
The medium inertia servo motor is suitable for medium load and moderate motion change.
For example, in an automated assembly line, the conveyor belt needs to carry a certain weight of products, but the speed is not particularly fast. At this time, the inertia motor can provide stable support. There are also electric sewing machines, which require precise speed control and sufficient force to push the needle through thick cloth. The medium inertia servo motor is very suitable.

high inertia servo motor
The rotor of this servo motor is heavier and suitable for heavy load and stable occasions.
For example, the use of high inertia motors for large manipulators to carry heavy loads ensures that the system remains stable at low speeds. There are lifting platforms, elevators, CNC machine tools, etc.

3. Inertia selection need to consider what?
Choosing the right inertia needs to consider the following points:
Load condition
First of all, we must understand the load to be driven by the servo motor. If the load is light and requires frequent start and stop, it is wise to choose a low inertia servo motor; if the load is heavy, medium or high inertia servo motor should be considered to ensure stability.
Response speed requirements
In situations where rapid response is required, such as high-speed robotic arms, low-inertia motors can quickly adapt to changes. In applications where constant speed is required, such as conveyor belts for heavy loads, high inertia motors are more suitable.
Accuracy requirements
Inertia matching also affects the accuracy of the servo motor. In applications with high accuracy requirements, it is very important to choose the right inertia. If the inertia ratio of the motor and the load is not appropriate, the response speed may be too slow, which will affect the overall accuracy. Therefore, for high-precision applications, the inertia servo motor is usually a better choice.
Start and stop frequency
If equipment needs to be started and stopped frequently, such as a robotic arm in a production line, a low-inertia motor can provide a quick response and reduce the hysteresis caused by inertia. For equipment that works continuously, such as mixers or constant-speed transport equipment, high-inertia motors are more appropriate.
We know that usually in the selection of servo system, in addition to considering the torque and rated speed of the motor and other parameters, we also need to first calculate that the mechanical system is converted to the inertia of the motor shaft, and then according to the actual action requirements of the machine and the quality requirements of the processed parts to specifically select the motor with the appropriate inertia size.
Therefore, Xiao Ao also provides you with a variety of small coup documents for the calculation of "inertia" of servo motors,Scan the two-dimensional code below and add a friend's comment "inertia", can be obtained.
As an independent innovator in the field of motion control and intelligent perception, Alton not only provides high-quality products and comprehensive motion control solutions, but also warmly welcomes you to create a win-win situation together with everyone, contributing to the accelerated integration of Chinese manufacturing and the world.

Inertia, Motor, Servo, Load, Servo Drive




