Many friends have reflected that the spindle has also experienced excessive heat during the use of the woodworking engraving machine. I don't know if this is normal or if the woodworking engraving machine is malfunctioning. In fact, we don't have to worry about it. As long as the temperature is not too hot, the spindle heating is basically normal. If the temperature is too high, you can ask professional maintenance personnel to see if it is faulty. Next, follow the CNC network Xiaobian to learn about the high temperature of the spindle of the CNC woodworking engraving machine.
Since the internal structure of the CNC engraving machine main shaft is composed of a core and a winding coil, it generates a certain amount of heat in the energized state, and even if the working time is long, it may even be hot. Then, to what extent is the spindle heat normal, how to reduce the heat it produces?
The temperature range over which the spindle heats up depends primarily on the internal insulation rating of the spindle. Under normal circumstances, the internal insulation performance will be destroyed at high temperatures (above 130 degrees). Therefore, as long as the internal does not exceed 130 degrees, the spindle will not be damaged, and the surface temperature will be below 90 degrees. Therefore, the surface temperature of the stepping spindle is normal at 70-80 degrees.
The simple temperature measurement method is useful for point thermometers, and can also be roughly judged: the hand can be touched for more than 1-2 seconds, not more than 60 degrees; the hand can only touch, about 70-80 degrees; a few drops of water quickly It is more than 90 degrees. Spindle heating generally does not affect the life of the spindle, and most customers may not be too worried.
However, severe fever can have some negative effects. If the thermal expansion coefficient of each part inside the main shaft causes a change in structural stress and a small change in the internal air gap, it will affect the dynamic response of the main shaft, and the high speed will easily lose the step. Therefore, the necessary control of the heat generated by the spindle should be performed. When the spindle temperature is too high, you can choose to stop the machine, rest for a while and then continue to work, you can also add a radiator outside the spindle to ensure that the heat of the spindle is released in time.
When the constant current drive skill is accepted, the stepper motor maintains a constant current at static and low speeds to connect the constant torque output. When the rate is high to a certain level, the internal back EMF of the motor rises, the current will gradually drop, and the torque will fall. Therefore, the heating environment caused by the copper loss is related to the rate. Static and low-speed, usually high heat, low heat at high speed. However, the environment of change in iron loss (although the proportion is small) is not entirely the case, and the whole heat of the motor is the sum of the two, so that the above is just the usual environment.
Eliminating heat is to eliminate copper damage and iron loss. There are two deviations in the elimination of copper losses, eliminating resistors and currents. This requires that even in the selection of models, even if the motor with small resistance and low rated current is selected, for two-phase motors, the motors in series can not be connected in parallel. But this often contradicts the requirements of torque and high speed.
To deal with the selected motor, the active semi-flow control function and offline efficiency of the driver should be enriched. The former actively eliminates the current when the motor is static, and the latter blocks the current. In addition, the subdivision driver has less harmonics due to the current waveform close to the sine, and less heat is generated in the motor. There are few measures to eliminate iron loss, and the voltage grade is related to it. The high-voltage drive motor will bring about the promotion of high-speed characteristics, but it also brings about the growth of heat. Therefore, it should be selected to meet the driving voltage grade, high speed, stability and heat, noise and other indicators.
