Micro Switch can be Applied to Electric Actuator
What is a push rod motor?
The push rod motor is actually also called an electric push rod, which is an electric drive device that converts the rotary motion of the motor into the linear reciprocating motion of the push rod.
After the motor is decelerated by the gear, it drives a pair of screw nuts. The rotary motion of the motor is turned into a linear motion, and the forward and reverse rotation of the motor is used to complete the push rod action. For example, complex actions such as rotation and shaking can be completed by various levers, rockers or linkages. By changing the length of the lever arm, the stroke can be increased or enlarged.
Classification of electric actuators:
1. According to the screw type: trapezoidal screw type, ball screw type, planetary ball screw type, etc.
2. According to the motor type: DC motor type, AC motor type, stepper motor type, servo motor type, etc.
It can be used as an executive machine in a variety of simple or complex technological processes to achieve remote control, centralized control or automatic control. Small electric push rods generally use DC electric push rods, because direct current is more safe than alternating current.
The main purpose:
The electric actuator is a general-purpose auxiliary drive device, which can be widely used in medical, furniture, household, electronics, electric power, machinery, metallurgy, transportation, mining, petroleum, chemical, lifting, transportation, construction, grain and feed processing industries. Novel and exquisite design, small size, high precision, complete synchronization, good self-locking performance, sanitation, direct motor drive, no need for pipeline air source, oil circuit, it is now widely used in production lines, automobiles, ventilation window openings, military industry, and stage , Textile, sewage treatment and other industrial equipment.
The electric actuator has the characteristics of reliable performance, sensitive action, stable operation, the same push and pull force, and good environmental adaptability. With the development of modern social science and technology and the improvement of people's living standards.
The application of electric actuators is no longer limited to applications in the industrial field, but is more used in life, and is widely used in medical equipment and health care equipment, smart buildings and household facilities, and the automotive industry.
Precautions for selection
The selection of electric push rods can be selected according to specific applications to meet different requirements. In different environments, any combination of push rods and motors, special function accessories, and different combinations of electric push rods have different functions and application fields. The selection of electric push rods is summarized as follows:
1. For some simple push and pull, we can use ordinary motors and trapezoidal screws to work. Generally, it can be used to realize simple push and pull of objects and require low precision applications.
2. If you are working in a stable environment, the electric actuator requires small thrust, small size, quietness and smooth operation. The electric push rod is driven by 24V/12V DC permanent magnet motor, aluminum alloy or stainless steel transmission stalk. This kind of electric push rod is mainly used in electric nursing beds, operating beds, traction beds, dental chairs, massage beds, treadmills, fitness equipment and medical treatment In the equipment industry, it is equipped with overload protection function and built-in backup battery.
3. If it is in some relatively demanding environments, such as when there are certain requirements for accuracy, efficiency and speed, we can configure potentiometers, Hall feedback, etc., or use servo motors or steppers. The cost of these motors is relatively high when combined, but their accuracy and efficiency are also very high, and the requirements for installation and maintenance personnel are also very high.
4. The application fields of electric push rods are the same, but different products have different technical requirements for the same type of electric push rods. Therefore, it is very important to choose the appropriate electric push rod specifications. How to choose an electric push rod depends on thrust. , Stroke, mute, working cycle mode, control mode, installation accessories and other factors.
The internal structure of the electric push rod
90% of linear electric push rods have a built-in limit switch, which can automatically stop the actuator at the end of the actuator stroke, whether in the extended position or the retracted position. Other main components include gearbox, lead screw and limit drive nut. Once it reaches the end of the stroke (extended or retracted), the limit switch can also be doubled. The gear is simply used to reduce the speed of the DC motor, thereby increasing the torque force. When converted to linear motion by the lead screw, it also provides more linear force. As you might expect, the lower the gear, the lower the force but the higher the speed. Changing these gears is our way to provide different speeds and forces for all electric actuators.
One of the most important parts of the electric actuator is built into the end of the limit micro switch. These are very important because without them, the actuator will try to keep moving even when it reaches the limit of travel. The result will be an internal mechanical failure, possibly a burn out of the DC motor, because it still wants to keep spinning.
The method used in the electric push rod to stop the movement of the electric push rod shaft at the end of each stroke is to cut off the power of the DC motor when the limit is triggered by using a micro switch. There are diodes on the micro switch, allowing you to reverse the polarity to change the direction, even if the limit switch is triggered, the motor can run in reverse. The diode works as a one-way street. Therefore, electricity can only propagate in one direction through the diode, not the other way around. Once the drive shaft retracts and no longer touches the extension limit switch, electricity passes through the limit switch again, allowing movement in both directions.
Huizhou Greetech Electronics Co., Ltd. is committed to producing and innovating various micro switches. For more details, please visit our website: www.greetech-switch.com / www.greetech.com