Driving Mechanism Of Manipulator

There are four main driving mechanisms used in manipulators: hydraulic drive, pneumatic drive, electrical drive and mechanical drive.
1. Hydraulic drive
Hydraulic drive manipulators usually consist of a drive system consisting of a hydraulic motor (various oil cylinders, oil motors), a servo valve, an oil pump, an oil tank, etc., and work by driving the manipulator actuator. Usually, it has a large grabbing capacity (up to several hundred kilograms or more), and its characteristics are compact structure, stable movement, impact resistance, vibration resistance, and good explosion-proof performance, but hydraulic components require high manufacturing precision and sealing performance, otherwise oil leakage will pollute the environment.
2. Pneumatic drive
Its driving system usually consists of a cylinder, an air valve, an air tank and an air compressor. Its characteristics are convenient air source, rapid movement, simple structure, low cost and easy maintenance. However, it is difficult to control the speed, and the air pressure cannot be too high, so the grabbing capacity is low.
3. Electrical drive Electric drive is the most commonly used driving method for manipulators. Its characteristics are convenient power supply, fast response, large driving force (the weight of the joint type has reached 400kg), convenient signal detection, transmission and processing, and a variety of flexible control schemes can be adopted. The drive motor generally adopts a stepper motor, and the DC servo motor (AC) is the main driving method. Due to the high speed of the motor, a reduction mechanism (such as harmonic drive, RV cycloid pinwheel drive, gear drive, screw drive and multi-rod mechanism, etc.) is usually required. Some manipulators have begun to use high-torque, low-speed motors without reduction mechanisms for direct drive (DD), which can simplify the mechanism and improve the control accuracy.
4. Mechanical drive
Mechanical drive is only used in occasions where the action is fixed. Generally, a cam-link mechanism is used to achieve the specified action. Its characteristics are reliable action, high working speed, low cost, but not easy to adjust. Others also use hybrid drive, that is, liquid-gas or electric-liquid hybrid drive.