Generally speaking, there are four kinds of driving systems used in industrial manipulator: hydraulic drive, pneumatic drive, electrical drive and mechanical drive. Among them, hydraulic drive and pneumatic drive are mostly used.
1. Hydraulic drive type
The hydraulic driving manipulator is usually composed of hydraulic motor (various oil cylinders, oil motors), servo valve, oil pump, oil tank, etc., which is operated by the actuating system of the driving manipulator. Usually, it has a great lifting capacity (up to several hundred kg), which is characterized by compact structure, smooth movement, impact resistance, vibration resistance and explosion-proof. But the hydraulic components require high manufacturing accuracy and sealing performance, otherwise oil leakage will pollute the environment.
2. Air driven
The driving system is usually composed of air cylinder, air valve, air tank and air compressor, which is characterized by convenient air source, quick action, simple structure, low cost and convenient maintenance. However, it is difficult to control the speed and the air pressure is not too high, so the snatch capacity is low.
3. Electric drive
The electric driving industrial robot is a more widely used driving mode of manipulator. It is characterized by convenient power supply, fast response, large driving force (holding capacity of joint type has reached 400kg), convenient signal detection, transmission and processing, and can adopt a variety of flexible control schemes. The driving motor generally adopts stepping motor, and DC servo motor (AC) is the main driving mode. Due to the high speed of the motor, the reduction system (such as harmonic drive, RV cycloidal pin wheel drive, gear drive, screw drive and multi rod system, etc.) is usually adopted. Some manipulators have begun to use direct drive (DD) with high torque and low speed motor without deceleration system, which can not only simplify the system, but also improve the control accuracy.
Industrial robot manipulator can be divided into hydraulic type, pneumatic type, electric type and mechanical type according to the driving mode. It has the characteristics of completing the expected work by programming, and has the advantages of both human and machine from the perspective of construction and performance.