Power-assisted device for new energy vehicles technical analysis of air compressors!
Air compressor is a basic product of modern industry, it is a device that provides air power. It is a device that converts original mechanical energy or electrical energy into gas pressure energy, and is a pressure generating device for compressed air. At present, there are mainly four products of domestic automobile air compressors.
Piston Air Compressor
From the perspective of the composition of the piston air compressor, the piston air compressor basically includes: exhaust valve, cylinder, piston, piston rod, slider, connecting rod, crank, suction valve, valve spring and other structures.
The air compressor of piston structure always has a remaining volume at the end of the exhaust process, and the compressed air in the remaining volume is expanded during the next suction. This reduces the amount of air sucked in, reduces efficiency and increases compression work. And because of the remaining volume, as the compression ratio increases, the temperature rises sharply. Staged compression can reduce the temperature of exhaust gas, save compression work, increase volumetric efficiency, and increase compressed gas displacement. Therefore, multi-stage compression is usually used to increase the output pressure. In order to improve efficiency and reduce air temperature, intermediate cooling is required.
The advantages of piston air compressor are simple structure, long service life, easy to achieve large capacity and high pressure output. The disadvantage is that there are many vulnerable parts, large vibration, high noise, low reliability, and because the exhaust gas discharge is intermittent, the output has pulses, and a gas storage device is required during use.
Screw Air Compressor
Screw air compressor is a positive displacement gas compressor with a working volume for rotational movement. Compression of the gas is achieved by volume change, which is achieved by the rotational movement of a pair of rotors of the compressor in the casing.
The basic structure of the screw air compressor: In the main body of the compressor, a pair of meshing spiral rotors are arranged in parallel, and a rotor with convex teeth outside the pitch circle is usually called a convex rotor or an external thread. The rotor with concave teeth in the pitch circle is called the female rotor or internal thread, and the general male rotor is connected with the prime mover. The convex rotor drives the concave rotor to rotate the last pair of bearings on the rotor to achieve axial positioning and bear the axial force in the compressor. Cylindrical roller bearings at both ends of the rotor radially position the rotor and bear the radial force in the compressor. At both ends of the compressor body, openings of a certain shape and size are respectively opened. One is for suction, called the air inlet; the other is for exhaust, called the exhaust.
Screw air compressor has good reliability, low vibration, low noise, convenient operation, few wearing parts and high operating efficiency. The disadvantage is that the cost is high, the body is large and cannot be used in micro spaces, and the maximum pressure cannot be used in high pressure occasions.
sliding vane air compressor
The main body of the sliding vane air compressor is mainly composed of a rotor and a stator, in which longitudinal sliding grooves are formed on the rotor, and the sliding parts slide freely in it; the stator is a cylinder, and the rotor is eccentrically placed in the stator. A closed air compression chamber is formed between the two sliding vanes and the inner wall of the stator. When the rotor rotates, the volume of the compression chamber changes with the amount of sliding. During the suction process, air is drawn into the compression chamber through the filter and mixed with the lubricating oil sprayed into the main unit. During the compression process, the volume of the compression chamber gradually decreases and the pressure gradually increases, after which the oil and gas mixture is discharged through the exhaust port.
The whole machine of the sliding vane air compressor looks very simple, almost no spare parts can be seen. It uses air filter, intake valve, oil separator, safety valve, minimum pressure valve, oil filter, temperature control bypass valve, return valve and other components are all concentrated in the module in the form of a module. The sliding vane compressor has the advantages of high reliability, long-term continuous operation, excellent performance and low noise.
scroll air compressor
Scroll air compressor is formed by the interlocking of moving and stationary scrolls and two dual function equation lines. During suction, compression and exhaust, the stationary plate is fixed on the frame, and the moving plate is driven by the eccentric shaft and is restricted by the anti-rotation mechanism. The plane with a small radius rotates around the center of the static disk base. The gas is sucked into the periphery of the stationary disk through the air filter. Then it is continuously discharged from the axial hole in the central part of the fixed disk.
The unique working principle of vortex air compressor makes it the most energy-efficient compressor on the market. The low-wear working mode of the scroll compressor makes its life longer. It has the advantages of novel structure, small size, low noise, light weight, low vibration, low energy consumption, continuous and stable gas transmission, reliable operation, clean air source, etc. . It is widely used in industries such as industry, agriculture, transportation, medical equipment, food decoration and textile.
Conclusion
Through the analysis of the principle and structure of the above-mentioned air compressors, in the field of new energy vehicles: Although piston air compressors currently occupy a relatively high proportion, their low efficiency, high noise and high maintenance cost are not suitable for the future development requirements of new energy vehicles. .
Screw-type air compressor has reliable performance and high pressure; but with complex structure and large body, it is more suitable for applications in chemical, petroleum and mining industries.
sliding vane air compressor has many advantages such as low energy consumption, low noise, light weight, etc. It is more suitable for new energy vehicles and has a certain market share.
Scroll air compressors not only have the advantages of sliding vane air compressors, but also have the advantages of oil-free lubrication. The output air is very green, but the air output pressure cannot reach the pressure required by the automobile brake system. With technological innovation, the scroll air compressor has a bright future.
