As vehicle comfort standards continue to rise, NVH (Noise, Vibration, and Harshness) has become a critical factor in automotive design. While compressors and blowers are commonly recognized noise sources, small actuator motors inside HVAC systems are often overlooked.
In applications where air flaps are frequently adjusted, compact brushed DC motors such as SF-266 / 2126-size motors generate noise and vibration during start-stop and commutation processes. These micro-level disturbances can be amplified within the cabin, directly affecting user experience.
Generated by air movement driven by the blower, typically influenced by airflow speed and duct design.
The gear train inside the actuator produces meshing noise, especially when wear or poor alignment is present.
Noise generated by the motor itself, including electromagnetic and mechanical components, is a critical yet less visible contributor to NVH issues.
Brushed DC motors rely on physical contact between brushes and the commutator. This interaction creates periodic noise, particularly noticeable at low speeds or during frequent switching.
In small motors, rotor balance is essential. Any eccentricity or manufacturing deviation can lead to vibration, which is transmitted through the actuator housing.
HVAC actuators operate intermittently. Frequent motor startup and shutdown generate transient shocks, often perceived as clicking or tapping sounds.
The compact 21×26mm (2126) motor structure enables easy integration into confined dashboard spaces, but also introduces challenges:
Additionally, the interaction between the motor and gearbox significantly affects NVH performance. Poor lubrication or excessive backlash can worsen noise levels.
Optimizing brush materials and commutation design can reduce electrical noise generation.
Precise dynamic balancing minimizes vibration sources at the motor level.
Proper gear ratio and meshing design reduce motor load and prevent noise amplification under stress conditions.
Rubber dampers, mounting methods, and housing insulation all contribute to reducing perceived cabin noise.
Although small in size, actuator motors play a significant role in HVAC NVH performance. Through proper motor selection, structural optimization, and system-level integration, noise and vibration can be effectively minimized. For applications using SF-266 / 2126 motors, motor selection is not only about functionality, but also a key factor in achieving superior cabin comfort.
