Automobile air conditioning compressor.
Automobile air conditioning compressor is the heart of automobile air conditioning refrigeration system, which plays the role of compression and transportation of refrigerant steam.
Compressors are divided into two types: non-variable displacement and variable displacement.
Air conditioning compressors according to the different internal working mode, generally divided into reciprocating and rotating.
According to different working principles, air conditioning compressors can be divided into constant displacement compressors and variable displacement compressors.
Constant displacement compressor
The displacement of the constant displacement compressor is proportional to the increase of the engine speed, it can not automatically change the power output according to the needs of refrigeration, and the impact on the engine fuel consumption is relatively large. Its control is generally by collecting the temperature signal of the evaporator outlet, when the temperature reaches the set temperature, the electromagnetic clutch of the compressor is released, and the compressor stops working. When the temperature rises, the electromagnetic clutch is combined and the compressor begins to work. The constant 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 conditioning compressor
Variable displacement compressors can automatically adjust the power output according to the set temperature. The air conditioning control system does not collect the temperature signal of the evaporator outlet, but automatically adjusts the temperature of the outlet by controlling the compression ratio of the compressor according to the change signal of the pressure 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 dependent on the pressure regulator installed inside the compressor to control. When the pressure at the high pressure end of the air conditioning pipeline is too high, the pressure regulating valve shorens the piston stroke of the compressor to reduce the compression ratio, which will reduce the refrigeration intensity. When the pressure at the high pressure end drops to a certain extent and the pressure at the low pressure end rises to a certain extent, the pressure regulating valve increases the piston stroke to improve the cooling intensity.
According to the different working methods, compressors can generally be divided into reciprocating and rotary, common reciprocating compressors have crankshaft connecting rod type and axial piston type, common rotary compressors have rotary vane type and scroll type.
Crankshaft and connecting rod compressor
The working process of this compressor can be divided into four, namely compression, exhaust, expansion, suction. When the crankshaft rotates, the piston is driven by the connecting rod to reciprocate, and the working volume composed of the inner wall of the cylinder, the cylinder head and the top surface of the piston will change periodically, thus playing the role of compression and transportation of refrigerant in the refrigeration system. The crankshaft connecting rod compressor is the first generation compressor, which is widely used, mature manufacturing technology, simple structure, and low requirements for processing materials and processing technology, and relatively low cost. Strong adaptability, can adapt to a wide range of pressure and cooling capacity requirements, good maintainability.
However, the crankshaft connecting rod compressor also has some obvious disadvantages, such as the inability to achieve higher speed, the machine is large and heavy, and it is not easy to achieve lightweight. The exhaust is discontinuous, the air flow is prone to fluctuations, and there is a large vibration when working.
Due to the above characteristics of the crankshaft link compressor, there are few small displacement compressors using this structure, and the crankshaft link compressor is mostly used in the large displacement air conditioning system of buses and trucks.
Axial piston compressor
Axial piston compressors can be called the second generation of compressors, common swing plate or inclined plate compressors, which is the mainstream product in automotive air conditioning compressors. The main components of the inclined plate compressor are the main shaft and the inclined plate. Each cylinder is arranged in the central circle of the compressor spindle, and the direction of piston movement is parallel to the compressor spindle. Most inclined plate compressors are made of two-headed pistons, such as axial 6-cylinder compressors, then 3 cylinders in the front of the compressor, the other 3 cylinders in the rear of the compressor. Two-headed pistons slide in opposite cylinders, one piston compresses refrigerant vapor in the front cylinder, and the other piston draws refrigerant vapor in the back cylinder. Each cylinder is equipped with a high and low pressure valve, and a high pressure tube is used to connect the front and rear high pressure chamber. The inclined plate is fixed together with the compressor spindle, and the edge of the inclined plate is fitted into a groove in the middle of the piston, and the piston groove and the edge of the inclined plate are supported by steel ball bearings. When the spindle rotates, the inclined plate also rotates, and the edge of the inclined plate pushes the piston to reciprocate axially. If the inclined plate rotates once, the two pistons before and after each complete a cycle of compression, exhaust, expansion and suction, which is equivalent to two cylinders. If it is an axial 6-cylinder compressor, 3 cylinders and 3 double-head pistons are evenly distributed on the cylinder section, and when the spindle is rotated once, it is equivalent to the role of 6 cylinders.
Inclined plate compressors are relatively easy to achieve miniaturization and lightweight, and can achieve high speed operation. Its compact structure, high efficiency and reliable performance make it widely used in automobile air conditioning after realizing variable displacement control.
Rotary vane compressor
The cylinder shape of rotary vane compressor is round and oval. In a circular cylinder, the main shaft of the rotor has an eccentricity with the center of the cylinder, so that the rotor is close to the suction and exhaust holes on the inner surface of the cylinder. In an oval cylinder, the main axis of the rotor coincides with the center of the ellipse. The blades on the rotor divide the cylinder into several Spaces, and when the spindle drives the rotor to rotate one week, the volume of these Spaces constantly changes, and the refrigerant vapor also changes in volume and temperature in these Spaces. Rotary vane compressors do not have suction valves, because the blades can complete the task of suction and compression of refrigerant. If there are 2 blades, there are 2 exhaust processes for each rotation of the spindle. The more blades, the smaller the compressor exhaust fluctuations.
As the third generation compressor, because the volume and weight of rotary vane compressor can be small, easy to be arranged in the narrow engine cabin, coupled with small noise and vibration and high volumeefficiency advantages, it has also been used in automotive air conditioning systems. However, the rotary vane compressor requires high processing accuracy and high manufacturing cost.
Scroll compressor
This compressor can be called the 4th generation compressor. Scroll compressor structure is mainly divided into two types: dynamic and dynamic type and double revolution type. Dynamic turbine is the most widely used, and its working parts are mainly composed of dynamic turbine and static turbine. The structure of dynamic turbine and static turbine is very similar, both of which are composed of end plates and involute vortex teeth protruding from the end plates, and the eccentric configuration and difference between them are 180°. Static turbine is stationary, while the dynamic turbine is driven by eccentric rotating translational crank shaft under the constraint of special anti-rotating mechanism. There is no rotation, only revolution. 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, scroll compressors operate reliably, and it is easy to achieve variable speed movement and variable displacement technology. When multiple compression chambers work at the same time, the gas pressure difference between adjacent compression chambers is small, the gas leakage is small, and the volumetric efficiency is high. Scroll compressor has been used more and more widely in the field of small refrigeration for its advantages of compact structure, high efficiency and energy saving, low vibration and noise, and reliability, so it has become one of the main directions of compressor technology development.
Car compressor does not cool how to repair
The problem of car compressor not cooling can be repaired by the following steps:
Check the refrigeration system: First check the refrigeration system for leaks or blockages. The blockage can be solved by adding refrigerant to detect leaks and cleaning or replacing the filter element.
Check the compressor: If the refrigeration system is normal but the refrigeration effect is still poor, it is necessary to check the work of the compressor. If the compressor is found to be faulty, it needs to be repaired or replaced.
Check the fan: If the refrigeration system and compressor are working properly, but the refrigeration effect is poor, you need to check whether the fan is working properly. If the fan is faulty, repair or replace it.
Regular maintenance: In order to maintain the normal work of car air conditioning, it is recommended to regularly clean and maintain the car air conditioning system, including cleaning the evaporator, replacing the filter, etc.
Check the compressor belt: If the belt is too loose, it should be adjusted. Check whether the hose joint of the air conditioning system has oil stains. If the leakage is found, go to the maintenance department to solve it in time.
Clean the condenser: Regular cleaning of the condenser surface can greatly improve the cooling effect of the air conditioning refrigeration system.
Check the refrigerant level: Detect the refrigerant level by feeling the temperature difference between the inlet pipe and the outlet pipe of the dryer or by using the manifold pressure gauge.
Check the air conditioner control module: If the air conditioner control module is faulty, the air conditioner may not cool. Check its working condition to determine if it needs repair or replacement.
If the compressor is badly damaged, you may need to replace the compressor directly. During the maintenance process, if the electromagnetic clutch of the compressor is damaged, the electromagnetic clutch can be replaced separately, or a new compressor can be replaced. In addition, regular maintenance and inspection is also an important measure to prevent and solve the problem of car air conditioning is not cooling.
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