When it comes to precision machinery, the choice between a servo motor and a stepper motor can make a significant difference. One of the main differences between the two is their low-frequency characteristics. Stepper motors tend to suffer from low-frequency vibration at low speeds, which can be detrimental to the machine's operation. This is due to the nature of their operation, which results in a fixed resonance point. Many stepper motor drivers include automatic calculations of this resonance point, which adjust the control algorithm to suppress the vibration.
AC servo motors operate smoothly, even at low speeds, and have built-in resonance suppression functions. These motors have the ability to compensate for mechanical rigidity issues and include a frequency analysis capability that can detect mechanical resonance points, making system adjustments easier.
Another critical difference between servo and stepper motors is their operating performance. Stepper motors use open-loop control, which means that high starting frequency or heavy loads can result in a phenomenon known as missed steps or rotor lock. Likewise, stopping the motor at high speed can cause overshooting. To maintain control accuracy, acceleration and deceleration should be carefully managed. In contrast, AC servo motor drive systems use closed-loop control and directly sample encoder feedback signals. They include position and speed loops and do not suffer from missed steps or overshoots, resulting in more reliable control performance.
Choosing between servo and stepper motors for precision machinery depends on the specific requirements of the application. Factors such as the load characteristics, operating environment, and desired control accuracy should be taken into account. Nevertheless, it is clear that servo motors offer superior performance and reliability in comparison to stepper motors.
When it comes to precision machinery, the choice of motor can make a significant impact on performance and accuracy. Two commonly used motors in precision machinery are the servo motor and the stepper motor. While both motors serve a similar purpose, there are distinct differences in their design and performance.
Between servo and stepper motors is their torque-frequency characteristics. Stepper motors have a decreasing torque output as speed increases, and at higher speeds, the torque drops drastically. This limits stepper motors to a maximum operating speed of around 300-600 RPM. On the other hand, AC servo motors deliver a constant torque output within their rated speed range of typically 2000-3000 RPM, and maintain a constant power output above the rated speed.
Their speed response performance. Stepper motors can take up to 200-400 milliseconds to accelerate from zero to their working speed, which is generally in the few hundred RPM range. AC servo systems, on the other hand, have excellent acceleration performance. For example, a 400W AC servo motor from Delta can reach its rated speed of 3000 RPM in just a few milliseconds, making it a great choice for applications that require rapid start-stop control.
In highly demanding applications, the performance of an AC servo motor far exceeds that of a stepper motor. In China, while there is a wide range of industrial sectors, many are still catching up to the high-end products and accumulations needed for the development of advanced electronic devices. However, with constant innovation and development, the gap in precision machinery will soon be bridged.
Choosing the right motor for precision machinery is crucial, and understanding the differences between servo and stepper motors is essential in making the right choice. AC servo motors excel in high-speed, high-precision applications, while stepper motors are more suitable for low-speed and low-precision applications.
When it comes to precision machine tools, the choice of motor type can greatly impact performance. Two commonly used motor types for precision machines are servo motors and stepper motors. While both motors can achieve high precision, there are significant differences in their control accuracy.
Stepper motors, which come in both two-phase and five-phase hybrid types, typically have a step angle of either 1.8 or 0.9 degrees for two-phase, and 0.72 or 0.36 degrees for five-phase. On the other hand, AC servo motors achieve their control accuracy through a rotary encoder located at the back of the motor shaft. For motors with a 17-bit encoder, the driver receiver 131,072 pulses for every rotation of the motor, corresponding to a pulse equivalent of 0.0027466 degrees. This is roughly 1/655 of the pulse equivalent of a stepper motor with a step angle of 1.8 degrees.
In summary, while both servo and stepper motors can offer high levels of precision, the control accuracy achieved by servo motors can be significantly higher due to their rotary encoders. When selecting a motor type for a precision machine, understanding the differences in control accuracy can be essential for selecting the right motor for the job.
