1. Positive displacement compressors are divided into reciprocating piston type (referred to as reciprocating type) and rotary piston type (referred to as rotary type) according to their structure.
Both the reciprocating type and the rotary type are applied to different degrees in automobile air conditioner devices. The reciprocating compressor is the first model that is still widely used (for example: BOCK compressor, BITZER compressor). As far as the reciprocating compressor is concerned, the technology is relatively mature, and the production and use have accumulated rich experience. The material requirements are low, the processing is easy, and the cost is low. It can adapt to a wider range of pressure and cooling capacity, and has high thermal efficiency. The disadvantage is that due to the reciprocating operation of the piston, the power balance performance is poor, which limits the increase in the speed of the compressor, the structure is complicated, the wearing parts are many, and the maintenance workload is large. However, the rotary compressor has a rotary motion of the working volume and no reciprocating motion mechanism, so it has good dynamic balance performance, stable operation, low vibration, and high efficiency in its suitable working range. In addition, the rotary compressor has simple structure, small size, light weight, few parts and high reliability. However, the rotary compressor has a small displacement and is generally used in air-conditioning systems with small cooling capacity, such as car air-conditioning systems.
2. The driving mode of automobile air-conditioning compressor can be divided into two types according to its driving source, non-independent and independent.
The non-independent type is the main engine of the car to drive the compressor. This type of driving method is suitable for the car models where the main engine of the car has a surplus but the compressor power is not too large, such as cars, vans, and engineering vehicles. This drive mode occupies a small space and is easy to maintain. However, as the compressor consumes part of the power of the main engine, it will affect the acceleration performance of the vehicle, and the cooling capacity of the air-conditioning device will change with the change of the vehicle speed.
Independent type (or auxiliary type), that is, an additional engine is configured to drive the compressor. Since there is another special drive machine, there is no mutual influence between the driving of the car and the cooling effect of the air conditioning device. However, this driving method takes up a certain amount of car space, has high cost, high noise, and complicated maintenance of the auxiliary engine, so the application range is not wide.
Regardless of whether it is driven by the main engine or the auxiliary engine, the automobile air-conditioning compressor adopts the open type, that is, the power input end of the compressor main shaft extends out of the body and is connected to the driving machine through a pulley. A shaft seal is installed where the shaft protrudes from the body to prevent leakage of refrigerant.
Post time: Jul-15-2021