KH Series Low-Temperature Stepper Motors | Used in Foldable Smartphone Screen Durability Testing

● Encoder feedback
● Integrated stepper drives
● Rear shaft 

Foldable smartphone screen durability testing requires long-term, high-frequency, and stable folding operations in low-temperature environments (as low as -45°C), which demands motors with excellent low-temperature startup and operational characteristics. Low-temperature stepper motors are drive components specifically tailored for this application. The KH Series low-temperature stepper motors have been specially optimized for cold environments and can start directly at -45°C without preheating. Their use of low-temperature-resistant lubricants and flexible cables eliminates issues common in standard motors at sub-zero temperatures, such as grease solidification and cable insulation cracking. In foldable screen testing, low-temperature stepper motors are typically mounted within compact test frames using small flange sizes of 28 mm or 42 mm, precisely simulating the force of manual folding with a holding torque of 0.12–2.5 Nm. To accurately replicate the user experience across varying temperatures, these motors must withstand tens of thousands of reciprocating cycles daily. With a step angle accuracy of ±0.09°, they ensure consistent folding angles with every operation. Additionally, low-temperature stepper motors can be equipped with position feedback (such as magnetic or optical encoders) to monitor folding angles and speeds in real time, providing the basis for closed-loop control within the testing system. During continuous operation, the low-temperature stepper motor generates minimal heat, ensuring it does not disrupt the low-temperature environment within the test chamber. To address potential power outages during extended testing, the motor can be integrated with a safety brake that instantly locks the output shaft upon power loss, preventing the foldable screen from being accidentally stretched or twisted. Notably, the KH series offers custom shaft-offset options to accommodate specific eccentric load mounting requirements. The integrated driver option allows the low-temperature stepper motor to be controlled directly via I/O or bus interfaces, reducing the space required for external drivers. In the harsh environment of -45°C, the rotor inertia of the low-temperature stepper motor is optimized to prevent loss of synchronization caused by low-temperature viscosity. Testing has verified that a folding screen durability test rig using KH Series low-temperature stepper motors operated continuously for 3 million cycles without failure. Whether in single-fold or dual-fold smartphone designs, these motors deliver a smooth and quiet driving experience. Behind every qualified foldable smartphone lies the silent, millions-of-cycles contribution of a low-temperature stepper motor. Choosing a low-temperature stepper motor means choosing the ultimate pursuit of product quality.