UAZ cars are perhaps the most common SUVs in our country. The highest maintainability, simplicity of design, reliability - all these factors contribute to their popularity for many decades. Unfortunately, mechanics, no matter how reliable it may be, is still not eternal. Including electrical appliances. There are many failures in their work, but the most critical element is the electric current generator. We will talk about him today.
What is a generator
This is a device for converting the rotation of the crankshaft into electrical current. The generator is part of the vehicle's on-board electrical system. When the engine is running, the unit recharges the battery and provides the ignition system, service systems and the car itself with electric current. There are not many problems with his work. But in order to understand their cause, it is necessary to find out in more detail the principle of operation of thisdevices.
How the generator works
Structurally, the device repeats a conventional electric motor with the difference that the rotor is driven by a belt drive from the crankshaft pulley and, by its rotation, activates alternating current in the winding, which is converted into direct current using a rectifier unit.
But the magnitude of this current depends on the rotor speed and, accordingly, the engine speed. Therefore, the generator is equipped with an output voltage regulator, which stabilizes it. The mechanism works regardless of the rotor speed.
What characteristics does the generator have
UAZ in the factory version is a rather low-power car. In early releases, the output current of his generator was only 40A. Subsequently, the parameter increased to 60A. The design of the rectifier unit and voltage regulator has changed. What was the regular generator UAZ "Loaf"? Model 452 is a very unreliable unit. Fortunately, its problems can be easily recognized by the ammeter built into the dashboard. Another feature of the old generator is the voltage regulator, made in the form of a separate unit. If it malfunctioned, due to the self-excitation of the winding, the engine refused to stall when the ignition was turned off.
New generators have a different design and, accordingly, a different connection scheme. Here, the voltage regulator is built into the brush holder and is made as a single unit. The differences also apply to the drive belt.Old devices were driven by a narrow belt, new ones were driven by a wider poly V-belt. The UAZ "Patriot" generator is more powerful, with an output current of up to 120A, since this car has a lot of electrical consumers, which is not in previous models.
There are quite a few ways to connect a device. The fact is that depending on the type of generator (with an external voltage regulator or built-in), a variety of connections are possible. In all cases, the UAZ generator is connected using three wires. This is a common plus for the battery, the ignition switch, the control lamp and the voltmeter on the dashboard. There are quite a few connectivity upgrade options. And all of them require a fairly serious knowledge of the principles of operation of automotive electricians. Otherwise, at least a short circuit in the rectifier unit is possible.
As already mentioned, there are many modifications of UAZ generators. Many of them are installed only on specific engines, including UMP. Due to the fact that the timing drive on these engines is chain, the alternator pulley is combined with the coolant pump and the radiator impeller. It has a rather large size of the UAZ alternator belt. It is 1030 to 1238 mm long.
The main model is 6RK1220. In addition, there are modifications with power steering. For its pump, a separate drive belt of shorter length is installed. On a UAZ Patriot car, the timing drive is belt driven. What modifications doesgenerator belt? UAZ "Patriot" diesel type can be equipped with various such elements. On cars until 2012 - this is 6RK 2100 (one belt), after 2012 - with two belts 6RK 1220. When choosing a suitable element, you must be guided by the instruction manual, as well as the catalog of parts for a particular engine.
Dismantling the device
How is the alternator removed or replaced? UAZ "Loaf", like any other car, from time to time also requires maintenance or repair. It should be noted that the process of dismantling the device is somewhat different from that on the VAZ models - a longer belt, or even two, as well as driving auxiliary units that complicate the work. Before starting the operation, the negative terminal of the battery must be removed. Next, all wires and terminals are disconnected from the device itself, which generates current.
To remove the UAZ generator, you need to get the power steering belt (if any), loosen the generator tension bar and remove the belt completely. Unscrew the two bolts holding the top mounting plate. Next, a long bolt is unscrewed that secures the generator to the cylinder block from below. After that, the generator is successfully removed from the car. UAZ "Patriot" has some peculiarity - it does not need to remove the second belt, and the tension is regulated by a special roller. Installation of the device is carried out in the reverse order.
Possible mechanism improvements
The operation of the generator on UAZ vehicles raises many questions and problems.First of all, this concerns old structures and connections. The cardinal method is a complete replacement of the generator with installation on a suitable pulley removed from the old device, or a selection of a new one. Due to the fact that nowadays UAZs are used as off-road vehicles for hunting, fishing or extreme sports, a large amount of additional electrical equipment is installed on them.
The regular UAZ generator cannot cope with the increased load and requires the replacement of individual parts or the entire device in the event of, for example, a stator short circuit. But you can also modify the old mechanism by installing additional diodes in the rectifier unit. Motorists modify the voltage regulator. And if it is a new sample, then a three-level element with an external control unit is installed. The best results, of course, are obtained by replacing with a foreign generator (for example, from Toyota, at 120A). Refinement is reduced only to the replacement of the crankshaft pulley.
The most common breakdown is the breakdown of diodes in the rectifier unit (the so-called "horseshoe"). In this case, the entire unit is subject to replacement. Also, the UAZ generator fails due to the failure of the voltage regulator. Because of this, the voltage in the on-board network drops when the engine is running. The battery is undercharging. Also, during operation, the brushes in the brush assembly are erased. Here, too, the voltage in the on-board network drops under load. Due to the natural wear of the carbon brushes, they shorten and are less pressed against the slip ring during operation.
Another fault is the wear of the rotor axle bearings. It can be natural or caused by excessive tension on the alternator belt. In this case, to replace the bearings (there are two of them - front and rear), they should be pressed out of the seats and replaced with new ones. In all cases, the generator must be removed from the vehicle for maintenance and preventive maintenance. The condition of its drive belt affects the long-term and uninterrupted operation of the device. Scuffs and cracks are a sign of wear. This belt needs to be replaced immediately.
Thus, the correct and uninterrupted operation of the electrical equipment of the UAZ vehicle is largely based on the performance of the generator. And the wide possibilities for improving the voltage regulator and replacing other elements can significantly expand the capabilities of the electrical equipment system and adapt it to the consumption of a higher number of electrical appliances.