Servo Motor

More Powerful and Compact
The most apparent benefit of synchronous motors is their higher torque density relative to induction motors. A servo motor of a similar physical size to an induction motor will typically produce 40-60% more torque.
Reaching the required torque, speed, or power required by the application requires a servo motor that is smaller and more lightweight than its induction counterparts.
This efficiency makes a PM (Permanent Magnet) motor ideal for applications with space and/or weight constraints. Learn more about KEB’s DL4 series of high torque servo motors for large power industrial applications.

Low Inertia for High Dynamic Response
Because a servo motor is more compact, it inherently has lower inertia than comparable induction motors. With its low inertia, the synchronous motor can accelerate and decelerate to/from its rated speed much faster.
It also allows for much more precise starting and stopping from full speed, making synchronous motors ideal for highly dynamic or motion control applications.
Concerning motion control, servo motors are uniquely suited to packaging applications. These low-inertia motors work with EtherCAT Motion Controls to provide precise, coordinated motion. This flexible setup works well in almost any part of the packaging line, from tracking to sorting and forming.

Full Torque at Zero Speed
Another important benefit of the PM motor is that it continuously allows for full torque at zero speed – a stark difference from most induction motors, where the low-speed torque and stability are limited. VFD adjustments (e.g., Voltage Boost) can be made for low-speed operation, but this creates additional motor heating and limited performance.
Thus, if a holding torque at zero speed is necessary or if the application requires running at low speeds, a servo motor (with feedback) would be essential.

Higher IP Rated Protection
In addition to its benefits for motor control, servo motors typically have benefits in their housing designs. KEB’s synchronous motors do not require a cooling fan, which allows it to reach IP65 protection.
Induction motors, on the other hand, are commonly IP44 or IP54. If the motor is going in a harsh environment, a servo motor may be beneficial to prevent premature failure.
Servo motors feature a brushless design that suits them to demanding environments and applications. One example is the food and beverage environment, where machines may face steep temperature changes and washdowns.

Many industrial applications involving high pressure or temperature levels can benefit from a servo motor.

The Main Functions
(1)The servo motor itself also has function of generating a pulse current. Each rotation of an angle will emit a corresponding number of pulses that can be used by servo motors to form a response and a closed loop. In this way, the system can know the number of pulses it has already sent to the servo motor and how many pulses it has already received at the same time, through which it can control the rotation precisely and the positioning precision can reach 0.001mm.
(2)DC servo motor can be divided into brushed motor and brushless motor. In terms of brushed motor, it has edges in low cost, simple structure, large starting torque, wide speed range and easy control. But it needs to change carbon brushes. Although the change has no difficulty, it will cause electromagnetic interference and is burdened with environmental requirements. Therefore, it can be applied in common industry and civil applications that are sensitive to the costs.
(3)While brushless motors are featured by small size, light weight, great output, fast responding speed, small inertial, and stable rotation and torque. It is complex to control, but it is easy to be intelligent. Commutated by square wave and sine wave, the electronic commutation is flexible. The motor is free from maintenance and enjoys a high efficiency, low working temperature, subtle electromagnetic radiation, and a long service time. Besides, it can be applied in any environment.
(4)The AC servo motor can be divided into a synchronous motor and an asynchronous motor. Currently, the former is often applied in motion control. It has a large power range and can work with large power. With low maximum RPM and inertial which will rapidly decreases with the increase of power. Therefore, it is used in what requires low speed and stable operation.

The Advantages
(1)Having extraordinary response speed, the servo motor provides a large torque in the point-to-point fast positioning motion occasion, which makes the system have a extremely high dynamic response and greatly exceeds the limit of the traditional stepping system.
(2) The servo motor remains in the range of its rated speed range and belongs to constant torque output. And it has a variety of feedback adjustments to ensure the running accuracy of the servo motor and output torque.
(3)The Main Applications
*Machinery industry:Machining centers, CNC punching machines, bending machines, shearing machines, PLC program controllers, etc.;

*Printing industry:Drying board machine; printing machine, offset printing machine, rotary machine, laser phototypesetting, proofing equipment, automatic punching and inkjet printing machine, etc.;
*Medical industry:Monitor, B-ultrasound machine, CT control box, electrocardiogram ( EEG) tester, X-ray machine, etc.;
*Food industry: Sterilizer, homogenizer, labeling machine, can making machine, flow control instrument, sealing machine, etc.;
*Rubber tire industry: Steel wire belt ply production line, inner liner extrusion production line, steel wire calender, etc.;
*Elevator industry: Door control, floor control, etc.

There are several factors to consider when choosing a servo motor:
Torque: The torque requirement of the application should be matched with the motor's maximum continuous torque rating. It is important to select a motor that can deliver enough torque to power the load without overheating or stalling.

Speed: The speed requirement of the application should be matched with the motor's maximum speed rating. It is important to select a motor that can operate at the desired speed without overheating or losing accuracy.

Size and weight: The size and weight of the servo motor should be appropriate for the application. A larger, heavier motor may be more suitable for applications that require high torque, but a smaller, lighter motor may be more suitable for applications that require faster speeds or precise positioning.

Voltage and current: The voltage and current requirements of the servo motor should be compatible with the power supply available. It is important to select a motor that can operate at the available voltage and current without overheating or losing accuracy.

Feedback: The servo motor should have a suitable feedback mechanism, such as an encoder or resolver, to provide precise position and speed control.

Mounting: The servo motor should have a suitable mounting configuration for the application, such as a flange or shaft mount.

Environment: The servo motor should be suitable for the operating environment, including temperature, humidity, and vibration.

Precise motion. Choose precisely engineered and manufactured motors that work optimally with your choice of high-resolution feedback devices, low-latency fieldbus, high-quality cables and high-performance drive.

High torque and power density. By selecting a motor that provides the continuous and peak torque required for your application in the most compact form factor, such as the AKM2G series, you can build a lighter machine in a smaller footprint — or to increase the performance of an existing machine without redesigning the motor mounting.

Speed control and dynamic response. A servo motor with greater torque density and less inertia will provide greater dynamic response, improving the productivity of your machine. For the smoothest operation, consider a low-cogging motor design paired with a drive that features cogging compensation.

Feedback mechanisms. Understand the advantages of each type of feedback device, including simple, rugged Hall-effect sensors; resolvers that work well in extreme environments; high-resolution optical encoders; and other options. Many motors, such as the AKM and AKM2G, are designed to accommodate most feedback devices with minimal or no modifications.

Motor type. Servo motors are available in a wide range of designs and models, including AC and DC; brushed and brushless; housed, frameless and cartridge; rotary and linear; high, medium and low voltage; washdown and hygienic; submersible; and other options.