Why the structure of industrial robots is technical
Speaking of the structural technology of industrial robots has to bring up the current status of China's industrial robot industry:
As we all know, due to innate factors, the Chinese robot industry still lags behind developed countries such as Japan, the United States, and Korea in terms of monomers and core components. Although the introduction of China's robot industry has formed a relatively complete industrial foundation after 30 years of development, compared with developed countries, there is still a large gap, the industrial foundation is still weak, and key components are heavily dependent on imports.
The entire robot industry chain is mainly divided into upstream core components (mainly the three core components of the robot-servo motor, reducer and control system, which are equivalent to the "brain" of the robot), and the midstream robot body (the "body" of the robot) And downstream system integrators (95% of domestic enterprises are concentrated on this link) at three levels.
1.Industrial robot body
The robot body is the mechanical body of an industrial robot, and is an executive mechanism used to complete various operations. It is mainly composed of mechanical arms, driving devices, transmission units and internal sensors.
The mechanical interface of the last axis of the industrial robot body is usually a connection flange, which can be used to connect different mechanical operating devices, such as clamping claws, suction cups, welding guns, etc.
(1) Robotic arm
The robotic arm of an articulated industrial robot is a collection of many mechanical links connected by joints. It is essentially a space open-chain mechanism of anthropomorphic arms. One end is fixed on the base and the other end is free to move. The mechanical arm composed of the joint-link structure can be roughly divided into the base, the waist, and the arm (large Arm and forearm) and wrist 4 parts.
1) Base The base is the basic part of the robot and plays a supporting role.
2) Waist The waist is the supporting part of the robot arm.
3) Arm The arm is the part that connects the body and the wrist. It is the main moving part in the execution structure, also known as the main shaft. It is mainly used to change the spatial position of the wrist and end effector.
4) Wrist The wrist is the part that connects the end effector to the arm, also known as the secondary axis. It is mainly used to change the space attitude of the end effector.
The mechanism that drives the robot arm of an industrial robot to move. It uses the power element to make the robot move according to the command signal from the control system, which is equivalent to human muscles and muscles. There are three basic types of driving methods commonly used by robots: hydraulic drive, pneumatic drive, and electric drive. At present, except for individual robots with low motion accuracy, heavy loads or explosion-proof requirements, hydraulic,
In addition to pneumatic drive, industrial robots mostly use electric drives, and among them, AC servo motors are the most widely used, and most of the drive arrangements use one joint and one drive.
(3) Transmission unit
At present, the mechanical transmission unit widely used by industrial robots is a reducer. There are mainly two types of reducers applied to articulated robots: RV reducers and harmonic reducers. RV reducer is generally placed at the position of heavy load such as base, waist and boom (mainly used for robot joints above 20kg); harmonic reducer is placed at the position of light load such as forearm, wrist or hand (Mainly used for machine joints under 20kg). In addition, the robot also uses gear transmission, chain (belt) transmission, linear motion unit and so on.
1) Harmonic reducer
It usually consists of 3 basic components, including a rigid wheel with internal teeth, a flexible wheel that can produce radial elastic deformation and external teeth during operation, and an oval, outer ring with internal teeth mounted on the flexible wheel. The wave generator of the flexible rolling bearing can be fixed arbitrarily in the three basic structures, and the remaining one is a driving member and a follower.
2) RV reducer
It is mainly composed of sun gear (center gear), planet gear, swing arm (crank shaft), swing arm bearing, cycloid gear (RV gear), pinion, rigid disc and output disc. It has high fatigue strength and rigidity and long life, stable return difference accuracy, and high-precision robot transmission mostly adopts RV reducer.