Servo motors

What is a servomotor and how does it work?

From a technical point of view, most modern servomotors are synchronous motors with permanent magnets on the rotor. This design ensures high energy efficiency and excellent dynamics. However, what distinguishes a servo from a conventional electric motor is its operation in a closed feedback loop.

Every motor of this type is equipped with a measuring system. This can be a resolver, a tachogenerator, but most often it is an encoder. This device constantly monitors the position of the shaft and transmits this information to the controller. Thanks to this, the system knows whether the set position has been reached and can correct errors in fractions of a second. It is this continuous communication that makes servomotors indispensable where every micron counts.

The role of feedback - absolute and incremental encoder

The key to precision is the resolution of the measuring system. In our offer, you will find units equipped with:

Incremental encoder - a popular and economical solution that counts motion pulses. It requires homing the machine after every power loss. Models with a resolution of 1000 pulses per revolution or higher are often found, which is sufficient for most tasks.

Absolute encoder - a more advanced solution that remembers its position even after power is disconnected. This is invaluable in complex CNC machines and robots, where re-homing would be time-consuming or risky.

Key servomotor parameters

When selecting a drive for a machine, several key values should be considered. The basic one is torque. This is the force with which the motor can rotate the shaft. This value is given in Newton-meters. Depending on the size of the application, the demand for torque can vary widely. For precise packaging mechanisms, for example, a motor with a torque of 2.4Nm may be sufficient, while heavy machine tool axes may require units generating 20Nm or more. It should be remembered that a servomotor can maintain constant torque over a wide speed range, and also generate momentary overload torque, which is necessary for dynamic starting.

The second parameter is power. In our store, you will find a wide selection ranging from small motors with tens of watts, through popular 750W models, up to drives with 2kW or more power. Such a power range allows for ideal matching of the set to the inertia and mechanical resistance of the machine.

Speed is also important. Servodrives are characterized by high maximum revolutions, often exceeding 3000 or even 5000 rpm, while maintaining full operational stability.

Easy Servo and Motion Control Systems in Servomotors

The motor itself is only half the battle. To control it effectively, a suitable controller (servo amplifier) is needed. It converts signals from the master system (e.g., PLC or motion controller) into current supplying the motor windings. Modern controllers offer functions that once required separate motion control modules - from simple speed control, through electronic gearing, to complex electronic cams.

For users seeking a compromise between price and performance, an interesting alternative is Easy Servo technology (often designated by series symbols such as ES-M for motors and ES-D for controllers). This is a hybrid combining the features of a stepper motor with a feedback loop typical of a servo. This eliminates the risk of losing steps, which is a common drawback of open-loop control with conventional stepper motor drivers. Such a drive system is an excellent choice for 3D printers, plotters, or assembly machines.

Safety and operating conditions

The industrial environment can be challenging. Dust, moisture, and coolants are commonplace in production halls. Therefore, many of our servomotors have a high degree of protection, e.g., IP65. Such a compact design and sealing ensure the reliability of the drive even in harsh conditions.

Another important element that a servomotor is often equipped with is an electromagnetic brake. Its purpose is not operational braking (this is performed by the controller), but safe shaft locking after power failure. This is known as holding torque. This function is essential in vertical axes (e.g., elevators, robot arms), where gravity could cause the load to fall after the machine is switched off.

Servomotors - applications and integration

The natural environment for servomotors is industrial automation and robotics. They are responsible for the movement of robot arms from brands like Kuka and Fanuc. However, their application extends far beyond large car factories. They are the heart of packaging machines, labeling machines, filling machines, and CNC machine tools. Anywhere dynamics, positioning precision, and high production cycle efficiency are required, a servomechanism is the designer's first choice.

It is also worth mentioning mechanics. Often, to match the torque and speed to the receiver's requirements, a planetary gearbox is necessary. It forms a coherent rotary drive with the motor, increasing output torque and improving system stiffness. In some applications, linear drives are also used, which eliminate the need for belts or lead screws, offering even higher precision.

How to choose the right servomotor?

Choosing the right servomotor can seem complicated due to the multitude of parameters. However, it is crucial to determine the required torque (both nominal and peak), rotational speed, and load inertia. It is also important to pay attention to the flange size (e.g., the popular 80mm standard) for hassle-free installation.

By choosing a servomotor from our offer, you gain the assurance of receiving a proven product with high operating culture. Regardless of whether you need an advanced servo with an absolute encoder for an industrial robot, or an economical Easy Servo solution for plotter modernization – you will find devices with us that will ensure smooth and precise movement for your machines for years.

We encourage you to familiarize yourself with the offer of individual models. Our team of engineers will be happy to help you select the optimal set, taking into account the specifics of your applications and project budget. Remember that investing in a good drive is an investment in the quality of the final product.