After years of development, stepper motor drivers have been widely used in various types of automation equipment with the vigorous development of large-scale applications of domestic automation applications. According to the relevant statistics of the Ministry of Industry and Information Technology, the total number of domestic stepper motor driver sales reached about 10 million in 2014. If the number of dedicated ASIC stepper motor drivers integrated into the main board of the automation equipment control system is added, the overall The number of units has reached the scale of tens of millions.
At the same time of large-scale application, because the stepper motor driver is used as the power supply component of the stepper motor, it assumes the output control tasks of larger current and larger power. According to recent customer feedback, it has become an automated device. One of the most vulnerable devices. Through long-term research and analysis, we found that among these damages, in addition to the failure of end-users due to poor procurement of devices or poor production processes during the manufacturing of stepper drives, more than 50% of the damage is related to The shell and thermal design of the stepper driver are related!
In principle, the housing of the stepper motor driver should be made of aluminum with good heat dissipation characteristics. Because the heat loss of the stepper motor driver during work is greater than that of other types of motors, the housing and heat dissipation should be strengthened. The heat dissipation effect of the device is considered. However, from the actual situation, due to the consideration of cost pressure, some domestic stepper motor driver manufacturers' products take 57 stepper motor drivers as an example. Some manufacturers use plastic casings and reduce the weight of the radiator to the history. At the lowest level, the result is that the driver does not get good heat dissipation during long-term use, especially the life of the large-capacity capacitor inside it decreases rapidly, becoming the number one killer of product stability.
Looking at the external heat dissipation design solutions of stepper motor driver design manufacturers at home and abroad, especially the designs of Japanese manufacturers, of course, from the perspective of environmental protection, aluminum should be used less. However, whether the design of the cooling scheme is reasonable has become a crucial link. In principle, the more aluminum material used, the larger the volume (B) of aluminum, and the larger the area (S) of aluminum, the better the product's heat dissipation effect. However, it is easy to ignore that the distance (D) between the heat source and the core of aluminum with a large heat dissipation area is also one of the important factors affecting the heat dissipation of the stepper driver, but it has been ignored by product designers for a long time. After long-term observation and summary, the heat dissipation efficiency formula is: heat dissipation efficiency E = constant K * BSD. At the same time, the formula has achieved excellent results in different product designs.
The design of the shell and radiator of the stepper motor driver is not only considered from the perspective of aesthetics, the real core should return to the guarantee of heat dissipation efficiency and the service life of the core parts of the product!