Classification and characteristics of electric cylinders

Classification of servo electric cylinders

Servo electric cylinders can be divided into two types in terms of appearance and structure: linear type and parallel type.

1.Linear electric cylinder

The linear electric cylinder integrates servo motor, servo driver, high-precision ball screw or planetary ball screw, module design and other technologies. The entire electric cylinder has a compact structure. The transmission screw of the servo motor and the electric cylinder is connected through a coupling, so that the encoder of the servo motor directly feeds back the displacement of the piston rod of the electric cylinder, reducing the inertia and clearance of the intermediate links and improving the control performance and control accuracy. The servo motor is integrally connected with the electric cylinder, making it easy to install and set. The main components of the electric cylinder are all high-quality products at home and abroad, with stable performance, low failure rate and high reliability.

2. Parallel electric cylinder

The motor of the parallel electric cylinder is installed parallel to the cylinder body, and is connected to the transmission screw rod of the electric cylinder through a synchronous belt and a synchronous pulley. In addition to having the characteristics of a linear electric cylinder, the installation position is relatively small due to the short overall length. more suitable for the occasion. At the same time, the synchronous belt used in the parallel electric cylinder has the characteristics of high strength, small gap, and long life. The entire electric cylinder has high controllability and control accuracy.



Main features of electric cylinder

Due to its unique performance characteristics, electric cylinders have been gradually promoted and used in many industrial situations. As a novel electromechanical integration product, its advantages are mainly reflected in the following aspects.

1. Energy-saving and clean, long life, simple operation and maintenance, and strong environmental adaptability. The servo electric cylinder is not easily affected by the ambient temperature and can work normally without failure in harsh environments such as low and high temperatures, rain and snow. The protection level can reach IP66. The seal prevents dirt and water contamination outside the cylinder and prevents the leakage of internal lubricant. It works for a long time and achieves high strength, high speed, high-precision positioning, smooth movement and low noise.

2. High transmission efficiency. Electric cylinders that use precision transmission components such as precision ball screws or planetary roller screws eliminate a lot of complex mechanical structures, and their transmission efficiency is greatly improved. The transmission efficiency of these types of electric cylinders can reach more than 90%.

3. High positioning accuracy. The servo electric cylinder using ball screw can achieve precise positioning of about 0.01mm through servo control. It has high positioning accuracy and is suitable for applications that require relatively high accuracy.

occasion. Electric cylinders can achieve very high positioning accuracy in semi-closed loop, while hydraulic cylinders and air cylinders must use fully closed-loop control systems to achieve the same positioning accuracy.

4. Simple structure, small space occupied and easy maintenance. The electric cylinder is mainly composed of a motor and a nut and screw mechanism. The mechanism is simple, small in size, and does not take up too much working space. Due to its simple structure, it is easy to find the cause of the fault when a fault occurs, and daily maintenance is also very convenient.

5. High reliability and safety. Electric cylinders can be equipped with advanced sensor systems and various stroke control devices to detect and provide feedback on the working status of the electric cylinder to prevent accidents.



6. Stable operation and long service life. When the electric cylinder uses a ball screw or planetary roller screw, the friction in the transmission part will be greatly reduced, which will help reduce material wear, improve operating stability, and extend service life.

7. Fast response, linear working speed can be adjusted within a wide speed range, and low-speed operation is stable. The working speed of hydraulic cylinders can generally only reach 35mm/s, but the working speed of ordinary electric cylinders can generally reach 55mm/s. The speed of the electric cylinder using a planetary roller screw can even reach 2000 mm/s, and the speed advantage is very obvious. In addition, hydraulic cylinders are prone to crawling at low speeds and heavy loads, while electric cylinders do not have this shortcoming.

8. Precise control and good synchronization. When multi-drive synchronization is required, it is difficult to achieve high-precision synchronization using hydraulic cylinders or pneumatic cylinders because the control loop frequency characteristics of multiple independent hydraulic cylinders or pneumatic cylinders are consistent.

It's a very difficult thing. However, it is easy to achieve synchronization using multiple electric cylinders because the frequency characteristics of the electrical system are relatively easy to achieve consistency.

9. Electric cylinders can also replace some hydraulic cylinders and pneumatic cylinders. The components that can achieve linear transmission mainly include electric cylinders, hydraulic cylinders, and air cylinders. The main differences between the three are as shown in the table below. It can be seen from the comparison that the electric cylinder has a simpler structure than the hydraulic cylinder and the air cylinder, and is less affected by temperature fluctuations.