ASLONG 25 Series DC Motor: Problem and Solution Case Study

I. Problem Identification

• Motor Overheating: The motor tends to overheat when operating under high load or for extended periods, which not only reduces its efficiency but may also lead to motor damage.
• Insufficient Speed Control Precision: In applications that require precise speed control, such as robotic joint movement or smart car path planning, the motor's speed control precision is not high enough, resulting in speed fluctuations.
• Short Motor Lifespan: Under conditions of frequent start - stop cycles or high - load operation, the motor's lifespan is relatively short, necessitating frequent replacements.

II. Problem Analysis

1. Motor Overheating
   • Cause: When the motor operates under high load, the resistance of the internal windings generates heat. Poor heat dissipation can further exacerbate the overheating. Additionally, the friction of the internal bearings also produces heat. If the heat - dissipation design is not rational, the heat cannot be dissipated in time, leading to a rise in motor temperature.
   • Impact: Overheating of the motor can cause the insulation material of the windings to age, reducing the motor's insulation performance and potentially causing short - circuits that lead to motor damage. Moreover, high temperatures can also decrease the motor's efficiency and increase energy consumption.
2. Insufficient Speed Control Precision
   • Cause: The precision of a motor's speed control is influenced by various factors, including the design of the control system, the mechanical characteristics of the motor, and load variations. If the response speed of the control system is not fast enough or if the mechanical inertia of the motor is too large, the precision of speed control can be compromised.
   • Impact: In applications that require precise speed control, such as robotic joint movement or smart car path planning, insufficient precision in speed control can result in decreased operational accuracy and reliability of the equipment.
3. Short Motor Lifespan
   • Cause: The lifespan of a motor is affected by various factors, such as brush wear, bearing fatigue, and winding aging. Under conditions of frequent start - stop cycles or high - load operation, the wear or aging rate of these components can accelerate, thereby shortening the motor's lifespan.
   • Impact: A short motor lifespan increases the maintenance cost of the equipment, reduces its reliability and stability, and affects the user experience.

III. Solutions

1. Solution for Motor Overheating
   • Improved Heat - Dissipation Design: Optimize the heat - dissipation structure of the motor by increasing the surface area of heat sinks or using more efficient heat - dissipating materials to enhance the cooling efficiency. For instance, using aluminum heat sinks can effectively increase the cooling area and lower the motor temperature.
   • Optimized Winding Design: Select insulation materials with higher heat resistance ratings to improve the thermal stability of the windings and extend their service life.
   • Added Temperature Sensors: Install temperature sensors inside the motor to monitor its temperature in real - time. When the temperature exceeds a set value, automatically activate a cooling fan or reduce the motor power to prevent overheating.
2. Solution for Insufficient Speed Control Precision
   • Optimized Control Algorithms: Implement advanced vector control or direct torque control algorithms to improve the precision and response speed of motor speed control. These algorithms can precisely regulate the motor's speed and torque based on its real - time operating conditions.
   • Feedback Mechanism: Introduce encoders or Hall sensors into the motor system to monitor the motor's speed and position in real - time. Adjust the motor's operating state through feedback - based control to ensure the precision of speed control.
   • Reduced Mechanical Inertia: Optimize the mechanical structure of the motor to reduce the inertia of the rotor, enabling it to respond more quickly to speed change commands and thus improving the precision of speed control.
3. Solution for Short Motor Lifespan
   • Optimized Brush Design: Use high - quality brush materials with better wear resistance and contact performance to extend the service life of brushes. Additionally, optimize the brush structure to reduce the friction between the brushes and the commutator.
   • Added Lubrication System: Add a lubrication system to the motor's bearing areas to automatically replenish lubricating oil regularly, reducing bearing wear and extending their service life.
   • Strengthened Quality Control: During the motor manufacturing process, strictly control quality to ensure the precision and reliability of each component. For example, use high - precision machining equipment and rigorous inspection procedures to minimize component errors and defects, and improve the overall quality and reliability of the motor.

IV. Implementation Results and Verification

1. Overheating Issue: Through improvements in heat - dissipation design and winding materials, the temperature of the motor during high - load operation has significantly decreased, with the highest temperature dropping by approximately 20°C. Moreover, the addition of temperature sensors has enabled the motor to automatically adjust its power output, effectively preventing overheating and extending its service life.
2. Speed Control Precision Issue: After optimizing control algorithms and incorporating feedback mechanisms, the precision of the motor's speed control has been substantially enhanced, with speed fluctuations reduced to within ±1%. In applications such as robotic joint movement and smart car path planning, the equipment's operational precision and stability have been markedly improved.
3. Short Lifespan Issue: By optimizing brush design, adding a lubrication system, and strengthening quality control, the motor's service life has been extended by approximately 50%. Under conditions of frequent start - stop cycles and high - load operation, the motor's failure rate has been significantly reduced, decreasing maintenance costs and downtime.

V. Conclusion and Future Outlook