How Do I Suppress Heat Generation in Stepper Motors?


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They’re worried about the heat generation in stepper motors...
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What’s wrong, Vex?
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Oh, Ms. Ori. A customer is concerned about the heat generation in stepper motors and asked if there was any way to reduce it.
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Ah. And what did you say, Vex?
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I can think of few ways to reduce heat generation, but I was wondering if there is a better method.
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I see. Let's start by considering the features of stepper motors. What kind of motor is a stepper motor?
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It's a positioning motor, so it's used in applications where stopping accuracy is requested. Since the rotation angle and rotation speed can be precisely controlled by pulse signals, detailed and accurate positioning is possible, and the excellent acceleration and responsiveness are suitable for applications that require frequent starting and stopping.
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Exactly! That feature is used in machines that feed film at regular intervals and machines that rotate turntables at regular angles. Now, let's consider the causes of heat generation, shall we?
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OK. The main cause is frequent driving, right? With stepper motors, regardless of load size, the operating current (=rated current) flows through the motor while it is in operation, and half the operating current flows through it while it is stopped, so the shorter the stop time, the higher the heat generated.
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That's right. So what are some possible ways to reduce heat generation?
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Adopting a longer stop time...
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Correct! Are there any other ways you can think of?
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If there's enough torque, you reduce the motor's operating current or use a fan for forced cooling.

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Yes. You’ve been studying hard, Vex! Another way is to use the all windings off function or automatic current cutback function, which are functions of the driver. If the mounting method can be changed, there are also ways to increase heat radiation effectiveness, such as thickening the mounting plate or changing to aluminum, which transfers heat easily.
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Is there a different way? Such as changing the motor or...?
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Yes, there is a way to increase the motor size if space permits. The torque can be increased, and the operating current can also be lowered. But if you're going to change the motor, why not go with the new AR Series?
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Huh?
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The AR Series are "high efficiency step-out-less stepper motor and driver packages" that are a further evolution of the αSTEP non-step-out stepper motor and driver packages. They're energy efficient reduce power consumption by 40 % compared to conventional models! They can also reduce motor heat generation, allowing for high frequency operation, helping to improve takt time of the equipment!

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Is that so? It's amazing that the power consumption is reduced by 40 %...less loss and less heat generation!
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For a motor, heat generation = loss. If we can reduce the loss of the motor, we can save a lot of energy. By the way, it's said that motors account for as much as 50 % or 70 % of the industrial electricity consumed in Japan.
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Really! I did not know that!
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The motor conserves energy, but Vex, please try your best to give the customer full-power service.
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…Okay.