[Miss. Ori, Manager]
How to reduce heat generation of a stepping motor?
[Mr. Vex, Staff]
Mr. Vex: Ms Ori, i received an enquiry on how to reduce the temperature rise of a stepping motor. This customer is very concerned about that.
Miss Ori: So, how did you answer this question?
Mr. Vex:I came up with a couple of methods to reduce heat generation, but i was thinking about a better method.
Miss Ori: let's take a look at characteristics of the stepping motor. How is the stepping motor like?
Mr. Vex: It is used in equipment when there is a requirement for high accuracy positioning. Rotation angle and speed are controlled correctly by pulse signal and due to their excellent acceleration and response, it is suitable for usages that needs frequent starting and stopping.
Miss. Ori: Exactly! By applying the characteristics, they are used for machines to feed films at a fixed interval or machines to rotate the turntable at a regular angle. Then, let's took into the cause of heat generation.
Mr. Vex:Okay, the main cause is high frequent operation, isn't it? Regardless of the amount of load, operation current(=rated current) will flow into the stepping motor when it is running and the current will be half as much when it stops. Therefore,if the stop time is short, heat generation becomes high.
Miss. Ori: What idea do you have in mind to reduce heat generation?
Mr. Vex: Having longer stopping time.Having longer stopping time
Miss. Ori: Correct! Any other ideas?
Mr. Vex:If the motor has enough torque, the motor current can be lowered. Or a fan can be used in force cooling of the motor.
Miss. Ori:Yes, you have studied well, Mr.Vex. Likewise, there are methods such as function for all windings off or automatic current off driver function. If the installation method can be changed, the mounting plate can be thickened or replaced by aluminum that easily conveys heat to increase heat dissipation.
Mr. Vex:Is there any other method? For example, changing a motor.?
Miss. Ori:Yes, if space allows, we can make the size of the motor larger. The torque will increase and it can be used at a lower operation current. But if a motor is changed, a newly released AR series might be better.
The AR series are "stepping motor unit with high efficiency and no misstep" which is an improved type of closed loop stepping motor unit. It can save up to 40% less energy and electric power consumption compared to conventional one. Being able to reduce heat generation in motors, it allows highly frequent operations and contributes improvement in tact time of the equipment.
Mr. Vex:Hmm, a 40% decrease in the electric power consumption is great! Wow, both the energy loss and heat are greatly reduced!
Miss. Ori: For a motor, heat generation equals to a loss. If the loss in the motor decreases, a large energy saving can be achieved. It is said that electric power consumed by motors occupies 50% or 70% of that of the industry consumed in Japan.
Motors are energy-saving but you should work hard with full energy to serve our customers.
Mr. Vex:Thanks Miss Ori.