1. The distinction between electric push rod and electric cylinder
Electric push rod and electric cylinder are generally referred to as electric actuators. They use an electric motor to drive various 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 push 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, without special distinction between the two).
In simple terms:
Push rod:
It has low thrust, simple pushing and pulling (without positioning function), and should not be operated at high speed. It uses a DC motor. The transmission parts of small push rods are made of plastic gears, while those of large thrust push rods are made of worm gears.
Servo electric cylinder:
It can be accurately positioned, can use DC or AC power, has a large range of thrust, and the transmission parts are generally directly connected through transmission belts and couplings, with a long service life.
There are multiple 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 push rod can be analyzed as follows:
1. Structure
The internal nut of the electric push rod is an ordinary nut, and the internal structure clearance is relatively large. The motor used is mostly AC or DC motor, 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 mostly a servo motor or a stepper motor, and its internal clearance is almost zero, so the repeat positioning accuracy of the cylinder is high, and its application is more extensive.
The service life can be long (The total stroke can reach more than 100,000KM).
2. Accuracy
AC electric push rod accuracy: 0.2mm, DC electric push rod accuracy: 1-2mm. Electric cylinder accuracy: 0.01-0.02mm.
The electric push rod is made of ordinary trapezoidal or ball screws, which are usually connected to gear motors, turbine rods and other transmission methods. The efficiency is relatively low.
The servo electric cylinder usually uses ground ball screws or planetary ball screws, and it is directly coupled with the motor or synchronously connected with the pulley. The speed and efficiency are very high.
4. Speed
The speed of the electric push rod is generally less than 100mm/s.
The speed of the electric cylinder can reach 2m/s.
5. Control
The electric push rod can only control two positions, the origin and the end of the trip. The electric cylinder can start and stop at any position.
6. Thrust
The electric push rod is mainly used to achieve 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 push rod has a simple structure, low thrust, low operating frequency, simple control procedures, and low price. It is used as an executive mechanical component in various simple or complex manufacturing processes.
Electric cylinder, especially servo electric cylinder, has the characteristics of large thrust, long stroke, precise speed and position control, high speed, and higher price than push rod. It is more widely used.
2. Which is better between electric linear actuator and electric cylinder?
In short, electric cylinders (usually servo electric cylinders) are capable of accurate positioning, fast speed, high load, and long lifespan, and are mostly used in industrial equipment, aerospace fields, and are in a different category compared to electric push rods.
Electric push rods can only extend and retract simply, cannot be precisely positioned, and cannot withstand large pushing force. The smaller push rods 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 suitable to choose electric cylinders. If for consumer goods or devices with lower requirements, electric push rods can also be used.
