Motor carbon brushes are components that transmit electric current through sliding contact with the commutator (or slip ring); in DC motors, they work in conjunction with the commutator to maintain rotation. They are used in a wide range of equipment, from industrial motors to power tools. If carbon brushes wear out or commutation becomes unstable, it can lead to sparking or damage to the commutator, making them critical from the perspective of maintenance and downtime risks. Carbon brush materials include electrographite, natural graphite, and metal graphite, among others, and selecting the appropriate material based on the application and operating conditions is essential. Understanding how to assess lifespan and replacement timing based on brush wear, as well as how to diagnose…

While a motor is rotating, the torque it outputs is not entirely constant. Instantaneous torque undergoes slight periodic fluctuations, manifesting as variations in rotational force. These periodic torque fluctuations are known as “torque ripple.” Significant torque ripple adversely affects equipment performance, leading to vibration, noise, reduced positioning accuracy, and degraded controllability.This is a technical challenge that cannot be ignored, particularly in fields where smooth operation and precision are directly linked to quality, such as medical equipment, optical equipment, and industrial robots. In this article, after clarifying the basic meaning of torque ripple and its difference from cogging torque, we will explain the main causes of its occurrence and methods for reducing it from the perspectives of design, control, and motor…

The ability to accurately measure and control a motor’s rotational speed is critical, as it directly impacts equipment performance and stable operation (required specifications). “I want to know the formula for calculating rotational speed.” “I want to understand how voltage and torque affect rotational speed” “I want to explore methods for achieving precise speed control” To address these technical challenges, this article provides a technically grounded explanation—ranging from the basic calculation formula for DC motor rotational speed to the factors affecting rotational speed, how to interpret T-N characteristics (torque characteristics) and how to use PWM control and feedback control for practical speed control. We provide information that will be useful to engineers in fields where reducing speed fluctuations and maintaining…

As medical equipment continues to become smaller and more precise, the role played by the motors that drive it is growing year by year. Compact motors are now incorporated into many devices used in medical settings—such as dental treatment units, endoscopes, electronic pipettes, and surgical assistance robots—and serve as core components that support the functionality and performance of these devices.Motors incorporated into medical equipment tend to be subject to higher performance standards than general-purpose industrial motors. To achieve the operational precision required by the equipment, it is essential to select the optimal motor for the specific application—one that offers smooth rotation, low vibration, a long service life, and a compact design. In this article, we will explain the typical applications…

Inverters are power conversion devices used across a wide range of fields, from home appliances to Industrial equipment. They are recognized as a core technology supporting both daily life and industrial operations, enabling energy saving operation of air conditioners and refrigerators, motor control in factories, and smooth acceleration and deceleration in elevators. However, there are few opportunities to systematically understand the internal structure of these devices or how they interact with motors.In this article, we will explain everything step by step—from the basic definition and mechanism of inverters to their role in motor control, real-world application examples, and key points to keep in mind during implementation. We have organized the knowledge essential for design decisions for engineers involved in motor…

The number of poles in a motor is a basic specification indicating the number of magnetic poles formed inside the motor, and it is a parameter that influences rotational speed and torque characteristics. In the design and procurement of Micromotors, questions often arise regarding whether to choose a 2-pole or 4-pole motor, and how an increase in the number of poles affects performance.The number of poles is not a value determined in isolation; rather, the optimal solution is determined by balancing speed, torque, size, cost, and the technical requirements of each specific application. In this article, we will systematically cover the basics of motor pole count, its relationship to speed, and the approach to motor selection based on application. The…

In fields such as industrial equipment, medical equipment, and robotics, designs that balance miniaturization with the necessary torque are critical to product performance. Concerns such as “Can we increase the torque a little more while keeping the size the same?” and “We want to make the device smaller, but we’re worried about whether it can withstand the load” are recurring design challenges faced in development environments.In this article, we will provide a comprehensive explanation, covering everything from the basic mechanisms of compact high-torque Torque motors to typical methods for increasing torque, their main applications, and key points to consider during the selection process. We have also compiled frequently asked questions from the design field in a Q&A format. We hope…

In medical pumps used in clinical settings—such as infusion pumps, insulin pumps, and hemodialysis machines—motors that deliver medications and blood with precision are essential. Since even the slightest deviation in flow rate directly affects patient safety, these motors must offer high precision and reliability.Furthermore, with the spread of home healthcare and growing demand for portable devices, requirements for miniaturization, quiet operation, and energy efficiency are increasing year by year. On the other hand, as miniaturization progresses, trade-offs in noise and performance are more likely to occur, making motor selection a critical factor that determines the overall performance of medical equipment. In this article, we will first outline the role of motors in medical pumps and the performance requirements they must…

In medical pumps used in clinical settings—such as infusion pumps, insulin pumps, and hemodialysis machines—motors that deliver medications and blood with precision are essential. Since even the slightest deviation in flow rate directly affects patient safety, these motors must offer high precision and reliability.Furthermore, with the spread of home healthcare and growing demand for portable devices, requirements for miniaturization, quiet operation, and energy efficiency are increasing year by year. On the other hand, as miniaturization progresses, trade-offs in noise and performance are more likely to occur, making motor selection a critical factor that determines the overall performance of medical equipment. In this article, we will first outline the role of motors in medical pumps and the performance requirements they must…

When installing a motor into equipment, an inappropriate shaft mounting method can result in torque transmission loss due to slippage and abnormal vibration. In the worst-case scenario, there is a risk of accidents caused by parts falling off or equipment damage. In medical equipment and industrial precision equipment, even the slightest mounting defect can affect product performance and safety; therefore, it is essential to select the correct mounting method based on the shaft shape. Three main types of motor shafts are used: D-cut shafts, round shafts, and keyway shafts. Each differs in the fastening methods that can be applied, the torque they can transmit, and the difficulty of machining. This article explains the characteristics of each shaft shape and typical…