1. Piping technology: The piping technology determines that the working pressure of the system and the arrangement of components must follow certain rules, and the damage to the piping components will lead to the loss of system function and bring other dangers. 2. Intrusion of pollutants and dust; system pollution will lead to unstable system operation and sharp decline in component life.

A. Quantitative pump: Gear pump, screw pump, quantitative vane pump, quantitative radial piston pump, quantitative axial piston pump. B. Variable pump: Variable vane pump, variable radial piston pump, variable axial piston pump. C. Gear pump: A gear pump is a pump that relies on the change of the volume of the working space produced by two or more gears sealed in a housing during the intermeshing process to deliver liquid. The most basic form of the hydraulic pump is that two gears of the same size mesh and rotate with each other in a tightly fitted casing. The inside of the casing is similar to the "8" shape, and the two gears are installed inside. body fit tightly. The hydraulic oil enters the middle of the two gears from the suction port, fills this space, moves along the housing with the rotation of the teeth, and finally discharges when the two teeth mesh. Because the liquid is incompressible, the liquid and the teeth cannot occupy the same space at the same time, so the liquid is excluded. Due to the continuous meshing of the teeth, this phenomenon occurs continuously, thus providing a continuous discharge volume at the pump outlet, and the discharge volume is the same for each pump revolution. With the uninterrupted rotation of the drive shaft, the pump discharges fluid uninterrupted. ​

Due to the gradual development of my country's construction machinery industry and the guidance of a series of industrial policies, the liquid and gas tightness industry has grown rapidly in recent years. image.png According to incomplete statistics, in 2021, the total industrial output value of enterprises above designated size in my country's liquid and gas tightness industry will be 77.271 billion yuan, a year-on-year increase of 21%. Among them, the hydraulic industry completed 43.620 billion yuan, a year-on-year increase of 18.47%; the pneumatic industry completed 15.046 billion yuan, a year-on-year increase of 29.60%; the sealing industry completed 18.605 billion yuan, a year-on-year increase of 23.95%.

After 2015, the global hydraulic market gradually entered a mature stage, and the scale growth rate gradually slowed down. Since 2012, the scale of the domestic hydraulic market has shown an upward trend year by year, showing a certain periodicity, and its proportion in the global market has gradually increased. According to the data disclosed by the China Hydraulic Pneumatic Seals Association, the proportion of the domestic hydraulic market in the world will increase rapidly from 27.7% in 2018 to 32.01% in 2020. It mainly benefits from the improvement in the prosperity of the downstream market. The 2021 "Government Work Report" proposes to arrange 3.65 trillion yuan of local government special bonds to optimize the use of bond funds, give priority to supporting projects under construction, and reasonably expand the scope of use. The investment in the central budget is 610 billion yuan. Continue to support major projects that promote coordinated regional development, promote the construction of "two new and one heavy", and implement a number of major engineering projects such as transportation, energy, and water conservancy, which will drive the prosperity of the construction machinery industry in the future.

​The robotic arm refers to a high-precision, high-speed dispensing robot. The robotic arm is a complex system with multiple inputs and multiple outputs, highly nonlinear, and strong coupling. Because of its unique operational flexibility, it has been widely used in industrial assembly, safety and explosion-proof fields. The robotic arm is a complex system with uncertainties such as parameter perturbation, external disturbance and unmodeled dynamics. Therefore, there is also uncertainty in the modeling model of the manipulator. For different tasks, it is necessary to plan the motion trajectory of the manipulator joint space, so as to cascade to form the end pose.

advantage Compared with mechanical transmission and electrical transmission, hydraulic transmission has the following advantages: 1. Various components of hydraulic transmission can be arranged conveniently and flexibly according to needs. 2, light weight, small size, small motion inertia, fast response [2]. 3. It is easy to operate and control, and can realize a wide range of stepless speed regulation (speed regulation range reaches 2000:1). 4. It can automatically realize overload protection. 5. Mineral oil is generally used as the working medium, the relative moving surface can be self-lubricated, and the service life is long. 6. It is easy to realize linear motion. 7. It is easy to realize the automation of the machine. When the electro-hydraulic joint control is adopted, not only a higher degree of automatic control process can be realized, but also remote control can be realized. shortcoming 1. Due to the large resistance loss and leakage of fluid flow, the efficiency is low. If not handled properly, leakage not only pollutes the site, but may also cause fire and explosion accidents. 2. Since the working performance is easily affected by temperature changes, it is not suitable to work under very high or very low temperature conditions. 3. The manufacturing precision of hydraulic components is high, so the price is more expensive. 4. Due to the leakage of liquid medium and the influence of compressibility, strict transmission ratio cannot be obtained. 5. When the hydraulic transmission fails, it is difficult to find the cause; the use and maintenance require a higher technical level.