Automotive air-conditioning compressors are the heart of automotive air-conditioning refrigeration systems, and play the role of compressing and delivering refrigerant vapor. Compressors are divided into two types: variable displacement and variable displacement. According to different working principles, air-conditioning compressors can be divided into fixed displacement compressors and variable displacement compressors.
Compressors can be divided into reciprocating and rotary types according to different working methods. Common reciprocating compressors include crankshaft connecting rod type and axial piston type. Common rotary compressors include rotary vane type and scroll type.
The compressor is divided into two types: variable displacement and variable displacement. Air-conditioning compressors are generally divided into reciprocating and rotary types according to their internal working methods.
According to different working principles, air-conditioning compressors can be divided into fixed displacement compressors and variable displacement compressors.
Fixed displacement compressor The displacement of a fixed displacement compressor is proportionally increased with the increase of the engine speed. It cannot automatically change the power output according to the demand for refrigeration, and it has a greater impact on the engine fuel consumption. It is controlled by collecting the temperature signal from the air outlet of the evaporator. When the temperature reaches the set temperature, the compressor electromagnetic clutch is released and the compressor stops working. When the temperature rises, the electromagnetic clutch is engaged and the compressor starts to work. The fixed displacement compressor is also controlled by the pressure of the air conditioning system. When the pressure in the pipeline is too high, the compressor stops working.
Variable displacement air conditioner compressor The variable displacement compressor can automatically adjust the power output according to the set temperature. The air conditioning control system does not collect the temperature signal of the air outlet of the evaporator, but automatically adjusts the air outlet temperature by controlling the compression ratio of the compressor according to the pressure change signal in the air conditioning pipeline. In the whole process of refrigeration, the compressor is always working, and the adjustment of the refrigeration intensity is completely controlled by the pressure regulating valve installed inside the compressor. When the pressure at the high-pressure end in the air conditioning pipeline is too high, the pressure regulating valve shortens the piston stroke in the compressor to reduce the compression ratio, which will reduce the refrigeration intensity. When the high-pressure end pressure drops to a certain degree and the low-pressure end pressure rises to a certain degree, the pressure regulating valve increases the piston stroke to increase the refrigeration intensity.
Crankshaft connecting rod compressor The crankshaft connecting rod compressor is the first-generation compressor. It has a wide range of applications, mature manufacturing technology, simple structure, low requirements for processing materials and processing technology, and relatively low cost. Strong adaptability, can adapt to a wide pressure range and cooling capacity requirements, and strong maintainability.
Axial piston compressor Axial piston compressors can be referred to as the second-generation compressors. Commonly, there are rocker or swash plate compressors, which are the mainstream products in automotive air-conditioning compressors. The main components of a swash plate compressor are the main shaft and the swash plate. Each cylinder is arranged circumferentially with the compressor’s main axis as the center, and the direction of piston movement is parallel to the main axis of the compressor. The swash plate compressor is relatively easy to achieve miniaturization and weight reduction, and can achieve high speed operation. It has a compact structure, high efficiency, and reliable performance. After achieving variable displacement control, it is currently widely used in automotive air conditioners.
Rotary vane compressor As the third-generation compressor, the rotary vane compressor can be small in size and weight, easy to arrange in a narrow engine compartment, coupled with the advantages of low noise and vibration, and high volumetric efficiency. Get a certain application. However, the rotary vane compressor requires high processing accuracy and high manufacturing cost.
Scroll compressor Scroll compressors have many advantages. For example, the compressor is small in size and light in weight, and the eccentric shaft that drives the moving turbine can rotate at high speed. Because there is no suction valve and exhaust valve, the scroll compressor operates reliably, and it is easy to implement variable speed motion and variable displacement technology. Multiple compression chambers work simultaneously, the gas pressure difference between adjacent compression chambers is small, the amount of gas leakage is small, and the volumetric efficiency is high. Scroll compressors have become more and more widely used in the field of small refrigeration due to their compact structure, high efficiency and energy saving, low vibration and low noise, and working reliability. Therefore, scroll compressors have become one of the main directions of compressor technology development.