Components of the air-conditioning system, their organization and check

• Oil coolants
• Compressor
• Condenser
• Receiver-dehydrator
• Expansion valve
• Evaporator
• Accumulator
• Expansion tube

Compressor organization

1 – back cover of the compressor 2 – entrance aperture (is not shown) 3 – back cover pad 4 – distributive plastics 5 – valve system with leaf valves 6 – coupling electromagnet coil 7 – pulley (is not shown) 8 – driven coupling disk 9 – pulley bearing 10 – nave fastening key on a shaft 11 – nut 12 – lock ring of condensation 13 – border condensation 14 – sealing ring 15 – crack case 16 – compressor control valve 17 – reducing valve 18 – lock ring 19 – pulley with driven coupling disk 20 – coupling bolt 21 – pad 22 – sealing ring between a crack case and the block of cylinders 23 – block of cylinders with shaft and inclined washer in gathering 24 – sealing ring between back cover and the block of cylinders 25 – distance bushing 26 – ring of axial bearing 27 – axial bearing 28 – fan switches and low pressure switches 29 – drain aperture fuse 30 – key groove 31 – shaft 32 – sealing rings of reducing valve 33 – sealing rings of fan switches and low pressure switches 34 – sealing ring of control valve 35 – lock ring

The compressor rotates from transmission to the compressor muff pulley of the rotating moment by the cranked shaft pulley through driving belt. If on magnetic muff the pressure is not given, the compressor muff pulley only rotates only and the shaft of the compressor does not rotate. When giving pressure on magnetic muff, the muff disk and bush move back and connect with a pulley. Pulley and disk under action of magnetic forces become uniform and result in rotation of a compressor shaft.

The compressor, depending on the rotating shaft, transforms gaseous condition of the low pressure refrigerant going from the evaporator, into high pressure and high temperature gas. The oil moving together with a refrigerant, plays a role of greasing. The piston at rotation of the compressor is actuated by the sheave, depending on pressure lets out the appropriate amount of gas by changing the piston course and a turning corner of a moving disk.

The air-conditioning system operates at the big load and at small one:

At the big load:

Bellows under influence of the sucking side pressure growth is compressed. Thus, pin falls, and the ball under influence of a spring and pressure from the high pressure side, due to counteraction of a saddle, will be lowered. As a result, pass A is closed, and transition of pressure from the high pressure side into a crack case stops. Simultaneously, pass B opens, there occurs transition of pressure from crack case into the sucking side. Therefore, pressure of crack case falls, and the let out volume is increased because of growth of the piston course because under the influence of piston movement caused by reaction of the cylinder internal pressure, the moving disk takes a position with an inclination, appropriate to the maximal pressure.

At small load:

Since sucking side pressure is low, bellows extends also the ball rises to a saddle direction. Therefore, pressure of a crack case increases because pressure on the part of a high pressure passes into crack case. As a result, the let out volume decreases due to reduction of the piston course because the moving disk takes a position of the minimal pressure.

In case of removal of the compressor from the automobile, for performance of works on the maintenance service, the compressor oil is merged and thrown out, then oil of a refrigerant with density 525 is filled.

For oil drain, a fuse A is turned off.

Attention: removal of a fuse for release of oil and full release of oil from the compressor aperture is very important point.

On compressors of automobiles there can be installed two different from each other back covers. On one type there is no switch, and it is installed on the refrigerant line. On the other type of a back cover, except separate models, instead of the switch of low pressure switching-off, they use the switch of the refrigerating system fan, like in old models. Similar switches of low pressure switching-off of are installed on refrigeration line.

Checking of the compressor

Imagine if the compressor normally does not work, the reason of it consists basically: in the coil of an muff electromagnet, a switch, a safety lock, a relay, a V-shaped belt connecting parts of wires. Besides if there are no malfunctions in the muff electromagnet and in electricity cables, malfunction of the compressor is explained by jamming of details. Low pressure upon an exhaust outlet of the compressor, that is on the high pressure side, is due to insufficiency of the refrigerant amount, too small hose aperture from the sucking side or malfunctions of the compressor. In similar cases prior to the beginning of check of the compressor it is necessary to check up pressure from the sucking side, including temperature of exit air stream from the central ventilating aperture and to compare with the required standard value. Comparison of temperature and pressure allows to find out, whether there the refrigerant amount in the system is sufficient. At excessive losses of the refrigerant it is necessary to check up oil in the system.

All malfunctions of the compressor can be divided into four groups: extraneous noise, jamming, outflow, bad compression. Though the sound resonance does not cause problems, and not regular extraneous noise or jingle are caused by damage of details or excessive expansion of backlashes from rubbing.

• For stock-taking jamming after the muff switching-off from the power supply, they check whether the driven muff disk rotates well. If it does not rotate, the compressor is jammed.
• The reason of bad compression is a damage of internal condensation or corking of the compressor internal part. Also the reason of bad compression may be cases of insufficiency of a gas - refrigerant or corking of an internal contour, therefore before maintenance service of the compressor it is necessary to put in order the above-stated things all over again.
• At absence of malfunctions in work of the compressor, and also there is no jamming, they check the current in the coil of the muff electromagnet as it is required.
• Quantity of oil of the compressor check after taking out of verifying cork.
• When checking of the oil amount on each site, if, after having switched the conditioner, to fix speed of the fan on a maximum and to let it rotate with speed 800-1000 rev/min for approximately 20 minutes, the system will reach the normal condition of operation and will show some certain value of the oil amount being inside components. This amount looks as follows (compressor: about 60 sm³, evaporator: about 40 sm³ condenser: about 20 sm³, a drier about 20 sm³.

Attention: At too dirty condition of oil, it is replaced. Though usually the period of replacement of oil is 3 years after the beginning of application, in automobiles for commercial use it is changed as soon as possible (approximately in 2 years).

Repair of the compressor (general)

The common repair of the compressor is described in the second part (Works on maintenance service and repair).

In the automobiles using compressor V-5, there are big differences in installation of fastenings of arms, homing systems, place of connections of pulleys (there is also a difference in productivity), but the sequence of repair of separate details is approximately identical with repair of the compressors used on other automobiles.

At maintenance service of the compressor they achieve that cleaning of a workplace is important. Wiping of tools and pure cleaning of a place have the important value in exact performance of works on maintenance service. Connecting parts of the compressor and external parts should be cleared prior to the beginning of works on repair of the automobile and removal of the compressor. At clearing details it is necessary to use a cotton fabric.