1. The distinction between electric rod and electric cylinder
The electric rod and electric cylinder are generally called electric actuators. They use an electric motor to drive multiple screws to rotate and transform the rotary motion of the screw nut into a reciprocating linear motion.
In general, the working principle of the electric cylinder and electric rod is the same, which is to perform linear pushing, pulling and lifting actions.
However, strictly speaking, there are still many subtle differences between the two (referred to as electric linear actuator, with no special distinction between the two).
In simple terms:
Push rod:
It has low thrust, simple push and pull (no positioning function) and should not be operated at high speed. It uses a DC motor. The transmission parts of small connecting rods are made of plastic gears, while those of large connecting rods are made of helical gears.
Servoelectric cylinder:
It can be precisely positioned, can use DC or AC power, has a wide thrust range, and the transmission parts are generally directly connected through drive belts and couplings, with a long service life.
There are several control modes for servo electric cylinders (speed mode, position mode, torque mode), which can be selected according to requirements.
The specific differences between electric cylinder and electric rod can be analyzed as follows:
1. Structure
The internal nut of the electric rod is an ordinary nut, and the clearance of the internal structure is relatively large. The motor used is mainly AC or DC, so the repeated positioning accuracy is lower and the service life is shorter.
The structure of the electric cylinder is a screw structure. The electric motor used for the electric cylinder is mainly a servo motor or stepper motor, and its internal clearance is almost zero, so the repeated positioning accuracy of the cylinder is high and its application is more extensive.
Service life can be long (total travel can reach more than 100,000 km).
2. Accuracy
AC electric rod accuracy: 0.2mm, DC electric rod accuracy: 1-2mm. Electric cylinder accuracy: 0.01-0.02mm.
3. Material selection
The electric rod is made of common trapezoidal or ball screws, which are generally connected to gear motors, turbine rods and other transmission methods. The efficiency is relatively low.
The servo electric cylinder generally uses grounded ball screws or planetary ball screws and is directly coupled to the motor or synchronously connected to the pulley. The speed and efficiency are very high.
4. Speed
The speed of the electric rod is generally less than 100mm/s.
The speed of the electric cylinder can reach 2m/s.
5. Control
The electric rod can only control two positions, the origin and the end of travel. The electric cylinder can start and stop in any position.
6. Boost
The electric rod is mainly used to perform pushing and pulling actions, and the thrust is basically difficult to exceed 10 tons. For electric cylinders such as servo electric cylinders, the thrust can reach 35 tons or more.
In summary, the electric rod has simple structure, low thrust, low operating frequency, simple control procedures and low price. It is used as an executive mechanical component in several simple or complex manufacturing processes.
The electric cylinder, especially the servo electric cylinder, has the characteristics of large thrust, long stroke, accurate speed and position control, high speed and higher price than the rod. It is most widely used.
2. Which is better between electric linear actuator and electric cylinder?
In short, electric cylinders (generally servo electric cylinders) are capable of accurate positioning, fast speed, high load and long service life and are mainly used in industrial equipment, aerospace fields and are in a different category compared to rods electrical.
Electric rods can only extend and retract in a simple way, cannot be positioned precisely, and cannot withstand large pushing forces. Smaller pushrods use plastic gears and are generally used in equipment or devices with low requirements.
If used in industrial equipment with higher requirements, it is more appropriate to choose electric cylinders. If it is for consumer goods or devices with lower requirements, electrical rods can also be used.
