How to improve the commutation of DC servo motors

We have previously introduced in detail how to improve the temperature rise of the servo motor. It can be seen that the temperature rise problem may occur during the operation of this motor. For this problem, we should confirm the frequency and period of the mechanism's action, as well as the size of the current. situation, as well as the surrounding environment and other factors.

However, when the DC servo motor rotates, when the armature winding component passes through the brush from one branch to another branch, the direction of the current in the component changes. We call the change in the direction of the current in the component called commutation. , the time experienced during the commutation process is ly short, and the direction of the current changes in a very short period of time. In addition, the commutation element itself has inductance, so the self-induced electromotive force generated is very large. On the surface of the brush and commutator A spark was created. So how to improve the commutation of DC servo motor? And what do we need to pay attention to in the process of improvement?

An effective way to improve the commutation of DC servo motors is to install commutation poles, but the following points must be noted:

1. Select the commutation polarity correctly. The commutating pole polarity should be opposite to the next dominant polarity along the armature for electric motors and the same for generators.

2. The commutating winding must be connected in series with the armature winding.

3. The commutation pole magnetic circuit should not be saturated.

In addition, we should choose the brush reasonably, and then require the contact resistance between the brush and the commutator surface to be as large as possible, and the brush wear resistance should be good. DC servo motors generally use electrochemical graphite brushes. Low-voltage and high-current motors generally use metal graphite brushes. For servo motors that are particularly difficult to commutate, split brushes are generally used.

When the machine tool is turned on, the CNC operation appears normal, but in fact, the servo motor does not rotate. From the perspective of the servo driver and related components, it may be caused by the following reasons:

1. The armature wire is broken or has poor contact.

2. The "pulse enable" signal or the "control enable" signal is not sent to the driver.

3. The speed command voltage is poorly connected or disconnected.

4. For motors with brakes, it may be that the brake is defective or the brake is not energized and the brake is not released.

5. The DC voltage used to release the brake is not added or the rectifier bridge is damaged, the brake is disconnected, etc.