One characteristic of stepper motors is that the machining precision of components directly affects the motor’s vibration and noise level. To achieve greater torque output, the air gap between the rotor and stator of a stepper motor is very small. Therefore, the machining accuracy of parts has a direct impact on vibration and noise. In addition, the properties of electrical steel laminations, product structure and production process standards also influence the noise performance of stepper motors.

Changzhou Hetai Motor & Electric Appliance Co., Ltd. is a micro-motor manufacturer featuring innovative management modes and strong technical capabilities. High-precision production equipment and tooling guarantee the machining accuracy of all components.

Microstepping drive is the most common and straightforward method to reduce vibration and noise of stepper motors. Its primary function is to deliver smoother motor operation. Nevertheless, operating smoothness often remains unsatisfactory below 60 rpm even with microstepping enabled, in which case alternative improvement measures should be considered. German TMC ICs adopt silent chopper drive technology. Replacing conventional driver chips with such high-performance ICs helps lower noise levels effectively.

Motors with higher inductance are less prone to resonance compared to low-inductance counterparts. Even when resonance occurs, vibration and noise remain milder. Accordingly, reasonable parameter matching delivers positive results for mitigating or avoiding noise induced within resonance bands.

Fitting a stepper motor with a gearbox can increase its operating speed. Alternatively, adjusting the reduction ratio of geared motors also enables avoidance of resonance zones. However, adding a gearbox usually brings substantial cost increases. Furthermore, gearboxes have inherent backlash. It is necessary to confirm that backlash exerts negligible influence on the application or that countermeasures are implemented to eliminate such effects.

For certain applications, the aforementioned solutions cannot achieve satisfactory noise reduction. Medical infusion pumps serve as a typical example: they operate across a wide speed range and inevitably pass through resonance regions that generate significant noise. Such equipment is commonly deployed in intensive care units close to critically ill patients, hence extremely low noise is mandatory. If noise reduction remains inadequate after adopting the above methods, physical vibration isolation via damping pads can be applied for further noise suppression. Vibration damping rings are another option to achieve smoother operation, yet their high cost limits widespread adoption.

Replacing a 1.8° two-phase stepper motor with a 0.9° model generally improves noise performance. Likewise, switching from two-phase to three-phase or five-phase stepper motors usually yields quieter operation. However, these upgrades normally raise overall costs, including expenses for both motors and drivers. Customers designing their own drive circuits must account for circuit modifications, requiring comprehensive evaluation of time and financial costs.

Substituting standard stepper motors with stepper-servo motors can also reduce noise. However, costs will rise for both the motor and driver. Since stepper-servo motors require integrated encoders, the overall motor length increases, so available installation space must be taken into consideration during design.