how to choose linear actuator

                                                            SELECTING A LINEAR ACTUATOR

As we have seen already, actuators have myriad applications in different fields. But this doesn’t mean that all actuators are made equal. When purchasing an actuator, you should be able to know which suits your requirements best. Here is a comprehensive guide on how to choose the right actuator for your needs.


Step 1. Assess the movement required:

Does the object you need to move in your project require linear or rotary movement? Linear actuators are useful in exerting a mechanical force that would move an object in a straight line while rotary actuators, as the name suggests, generate circular motion.


Step 2: Consider the energy input:

Electrical actuators are becoming more and more popular due to their increasing sophistication and flexibility in handling various kinds of operations. But that doesn’t mean it's suited for every work out there. Consider hydraulic or pneumatic actuators if your work does not include electrical voltage input.


Step 3: Assess the precision level required:

Some actuators are ideal for heavy-duty work in rough environments, but they may not work well when it comes to handling smaller work like packaging which requires precision and the ability to repeat the same action hundreds or thousands of times.


Step 4 : Find out how much force you need:

The purpose of an actuator is to move or lift an object. Find out, in your case, how much this object weighs. The load capacity of an actuator decides how much it can lift, and although many actuators may look similar, their load capacity will vary. Before you buy an actuator, make sure the weight of your object matches the capacity of the actuator.


how to choose linear actuator


Step 5: Find out how far you need the object moved:

Distance, or stroke length as it is technically known, matters here. The stroke length decides how far your object can be moved. Manufacturers often sell actuators of varying stroke length.


Step 6: How fast do you want the movement to be:

The speed of the actuator is often an important factor for most people, depending on their project. Usually, projects that require actuators to exert high force would move slower than those that generate low force. Speed of an actuator is measured in distance per second.


Step 7: Consider the operating environment:

Does the actuator need to work in a rugged or rough environment, where dust or humidity is a concern? If this is the case, you would want to choose a product with higher protection rating.


Step 8: Decide on the mounting style:

Actuators in the market come in different mounting styles and understanding their benefits is necessary before buying an actuator. For instance, a dual-pivot mounting method in a linear electric actuator allows the device to pivot on both sides while extending and retracting. With this, the application gets to have two free pivot points while moving on a fixed path.


Conversely, stationary mounting, which secures the actuator to an object along the shaft, is useful for actions such as pushing a button. At this stage, you should be able to narrow down your options to a significantly smaller pool from where you started. From here, you will need to narrow down further. For instance, linear actuators come in different styles for different kinds of functions. Rod-style, for instance, is the most common and simple among them, with a shaft that expands and retracts. Track style, which does not change its overall length or size during operations are more suited when space constraints are an issue. There are also column lifts and other actuators that would be ideal for setting up TV and table lifts. Factors such as operating voltage and motor type may also be worth considering.

How electric actuators work

electric putter 

After the motor is decelerated by the gear, a pair of screw nuts is driven. The rotary motion of the motor is changed into a linear motion, and the forward and reverse rotation of the motor is used to complete the putter action. For example, through various levers, rockers or connecting rods, complex actions such as turning and shaking can be completed. By changing the lever arm length, the stroke can be increased or decreased.

Stroke control device

Worm gear and worm drive form: The worm on the motor gear drives the worm gear to rotate, causing the small screw in the worm gear to move axially, and the connecting plate drives the limit lever to move correspondingly axially. When the required stroke is reached, the limit block is adjusted by Press down the travel switch to cut off the power, and the motor will stop running (the same as the positive and negative control).

Gear transmission type: The motor drives the small screw rod mounted on the inner tube through the reduction gear, and drives the nut to be connected with it to make an axial running nut. When the set stroke is reached, the nut antenna presses the limit switch to disconnect the power. The motor Stop motion (same as reverse).

An optional power distribution device is used to display the travel status of the push rod operation. An encoder can also be added to achieve the complete travel in a few steps (ie, stop and go).


New and exquisite design, small size, high precision, complete synchronization, good self-locking performance, hygienic, direct motor drive, no need for pipeline air source, oil circuit, has been widely used in production lines, automobiles, ventilation window opening, military industry, stage , Textile, sewage treatment and other industries.

Differences between asynchronous motor electric actuators and synchronous motor electric actuators

The difference between the working principle of asynchronous motor electric actuator and synchronous motor electric actuator:

The work of synchronous motors is based on 'the magnetic field always goes in the shortest direction of the magnetic circuit', taking the loss of motor as an example. After the rotor has been excited, N and S poles appear; then the stator magnetic field rotates, and the N and S poles change with each other and always correspond to the magnetic poles on the rotor one to one.

So there is synchronisation. More importantly, the number of magnetic poles of the stator and the rotor must be the same, otherwise the motor cannot run.

And asynchronous motors rely on induction to achieve movement. The principle is that after the three-phase voltage is applied to the stator winding, a rotating magnetic field is formed. The guide bar on the rotor generates a potential because it cuts the magnetic field lines; and because the guide bar is connected, a current is generated. At this point, we thought of 'the charged conductor will move in a magnetic field' that was learned in junior high school. Therefore, such a motor is called an 'induction motor'.

For asynchronous or induction motors, the number of poles of the rotor is the number of poles of the stator. It can also be said that the rotor has no number of poles. (The above is an example of the armature winding on the stator). Asynchronous motors have no pivot / transition.

Application of electric putter in electric sofa

The electric sofa is completed by electric push rods and motors, which can effectively massage the tired body, and the comfort will be stronger. When the electric sofa is stretched in the lying position, it has supporting force from all parts of the head to the foot. It is like lying in a state of no center of gravity, which can promote blood circulation and be healthy. The pedal part that pops out from under the sofa is a one-piece, void-free design. The use of electric sofas can also fully reflect comfort.

Electric sofas generally have the function of height and inclination that can be adjusted electrically. The electric massage chair that realizes this function is mainly realized by electric push rods. Electric push rods are also called linear push rods, linear drives and linear drives. Linear electric push rods are a type of Mechanism device that converts rotary motion into linear motion. Linear linear actuators are mainly composed of electric actuators, control boxes, remote control boards, and cables. Electric actuators can achieve the functions of lifting, tilting and reversing according to different combinations of supporting motors, screws, control devices and travel switches. The electric push rod has a small size and a quiet design; and it has high safety, and its locking force can reach ten times of the push force, which is absolutely safe; easy to operate, all operations of the linear electric push rod are concentrated on a remote control board for flexible operation. Suitable for use in electric sofas.

Effectively guarantee high-precision measurement of electric actuators

Before we use the linear mechanism of the electric push rod, we need to measure the linear mechanism in almost all industrial applications, mainly to measure the force on the workpiece. In more traditional solutions, the force sensor often It is placed in the middle of the linear motion mechanism and the workpiece, which is actually on the transmission chain between the two.

Therefore, the installation of such sensors will bring relatively large practical difficulties to the entire project. The first is to select, purchase and calculate the sensors. The second is to design and install the machinery as connectors. Finally, not only the accuracy To maintain accuracy, it is also necessary to ensure that the bending torque will not affect the accuracy of the entire measurement.

When the linear motion mechanism causes a certain pressure on the workpiece, the sensor also needs to generate corresponding movements. At this time, it is necessary to consider that the signal cable of the sensor is not damaged. Because the cable is relatively vulnerable to damage during movement, we need to consider in particular whether it is flexible enough. Finally it is necessary to install a signal amplifier.

Many friends think that the surface-looking force detection system is relatively simple, but it is actually a relatively complicated project, so when we use it, we must not only combine electrical technology, but also pay attention to mechanical changes. If such problems cannot be effectively solved, it may lead to redesign and selection of components, and this situation will definitely cause the entire project to be delayed.

Electric actuator description

Electric actuators, also known as linear motors, can be considered as an extension of the rotary motors in terms of structure. Electric push rod is a new type of linear actuator mainly composed of motor push rod and control device.

The electric push rod is an electric drive device that converts the rotary motion of the motor into the linear reciprocating motion of the push rod. It can be used in various simple or complex technological processes as executive machinery to achieve remote control, centralized control or automatic control.

Notes on the purchase of electric actuators

Electric push rods are mechanical auxiliary equipment and are used in conjunction with other equipment. This involves installation dimensions. The product sizes of various manufacturers have approximate standards, but they are not exactly the same. In order to avoid affecting the installation due to size problems, be sure to design the size of the electric push rod into the equipment to be used when selecting the model, instead of processing the equipment first and then selecting the electric push rod. I want to use it, because the size is not suitable. Either the equipment or the electric putter solution is changed. Even if it is installed at the end, the performance of the whole set of equipment or electric putter will have some impact, and it will not fully exert its functionality.

In addition, the frequency of use must be considered when purchasing electric actuators. Generally, the models of various manufacturers are marked. The common is the working system. This should also be communicated with the manufacturers. There are many products on the market. The working frequency may not be reached, so customers with very low price products should pay attention to it and the performance will be reduced.

Advantages of electric putters over traditional putters

Advantages of electric putters over traditional putters

1. The controllable range of push-pull force can be adjusted steplessly, which is traditionally impossible.

2. automatic overload and overload protection device, traditional can not be achieved.

3. The stroke control is more accurate than traditional, and the operation is stable.

4. The electric push rod adopts a seamless and fully enclosed structure, which is light in weight, not easy to rust, easy to install and maintain, and has a longer life than traditional.

5. The traditional air pressure pipeline is easy to leak, the internal pressure is unstable, and the noise is large; the noise of the hydraulic cylinder is large. Longsheng's electric pusher has a built-in full air flow circuit device, which can be operated only by supplying power.