PUMP DOESN'T LIKE DRY DRYERS
It would seem that electric motors should “genetically hate” liquids in general and gasoline in particular. However, the anchor, collector and brushes of the electric gasoline pump are constantly bathed in gasoline.
A system in which the collector motor is present is a big fan of sparking, and gasoline - a big fan of burning, should work like a clock - this is obvious. The object of the next examination is fuel electric pumps for the car, the first in our country to master injection. It's about the Volga. The pump on it is located outside the gas tank - approximately under the rear seat. We managed to acquire four identical products - two of ours and two imported (photo 1–4). Note that import, as usual, is 4–5 times more expensive.
Since all pumps are non-separable, we first test them in action, and then get acquainted with the device. Not so much is required of them - to provide the necessary performance and develop the required pressure. How they cope with this is evident from the table.
Everything is in order with the free-flowing performance - the data obtained is consistent with reference information from the literature. But when working "on the cork" zeal was not enough for everyone. If both foreigners easily gave out their 8–8.5 kgf / cm2, and the Stary Oskol pump limited zeal to 5.2 (by the way, a good result), then the Siberian frankly was capricious. Pressure pulsations from 3.5 to 4.5 kgf / cm2 were accompanied by noticeable heating and increased noise.
Both the sellers and the repairmen warned us of the bad temper of domestic pumps - they say, they buzz, they are warming up and they have not served for more than six months. It’s all the more interesting because they have something so bad in them that they don’t have in foreign ones? Or vice versa, it is not laid down?
First we outline the general features. The electric motor and pump section are mounted in one housing. Since the DC motor requires the necessary polarity, the terminals for connecting the wiring differ: “plus” is smaller, with M4 thread, and “minus” is larger, with M5 thread. Gasoline is pumped through the entire engine, cooling it. The non-return valve in the outlet fitting prevents the fuel from draining from the system after turning off the fuel pump. The pump section is equipped with a safety valve.
We turn to the highlights. The Boshevsky and Tyumen pumps resemble a pair of “Prince and the Pauper” - an absolute outward resemblance at a very different cultural level. Structurally, the pumps are the same - the pump section is located on the fuel inlet side of the pump, and its working element is an eccentrically located disk rotor with five slots. In the slots are cylindrical rollers playing the role of a seal between the five sections of the pump. During operation, each such section, due to the eccentricity, constantly changes its volume, increasing it when passing through the fuel intake zone. The resulting vacuum draws gas into the pump.
An interesting design feature is a single fixed axis for the rotors of the pump section and the electric motor. This solution allows you to do without a pair of "shaft - bearing", which wears out during operation. The consequences are known - skew of the rotor, fuel leakage, poor contact of the brushes with the collector, etc. Here the motor stator is two segments of permanent magnets fixed by spring holders in the steel cylinder, which also serves as a spacer between the pump section and the brush holder.
And where are the differences? Firstly, in the Tyumen version, the strainer at the pump inlet disappeared - an incomprehensible and unforgivable simplification. Secondly, pay attention to photo 5 - it is difficult to mix up the “twins”. The sparkling "German" looks clearly better … The price of success is attention to detail. In the Boshevsky pump there are no flaky magnets and skewed rubber seals, and its anchor does not turn whitish after bathing in gasoline. Strange pieces of wire do not protrude from the winding of the rotor - maybe it was because of them that the Tyumen pump could not work out normally?
The Stary Oskol pump is smaller and simpler. Collector brushes are located along the axis of rotation of the rotor. The working element of the pump section is the familiar five-roller disc rotor. Its axis is stationary, and the connection to the electric motor shaft is through the coupling. For some reason, there is no fine filter in the pump.
The pump section of the Pirburg product is made differently - it looks like the Samara oil pump. Instead of rollers used gears of internal gearing. The small (driving) gear of the pump is centered by the rotor shaft of the electric motor, and the rotation from the rotor to the gear is transmitted through a three-segment clutch. The bearing for the rear support of the rotor shaft is the pump section housing. At the entrance is a filter mesh cup.
Looking at the sparkling elements of the pump sections (photos 6 and 7), you realize how easy it is to disfigure them with dirty gasoline. After all, even a good fuel fine filter is not able to trap all the dirt - its residues will be grinded with rollers or gears. Hence, there are badasses, and even jamming … What then can we expect from pumps whose creators saved on the built-in filter?
The second trouble of beautiful “mechanics” is dry friction. With the cessation of gasoline supply, the pumping part is likened to Ichthyander, taken to the desert. Gasoline is cooling and to some extent lubrication. Therefore, even short-term dry running of the pump is extremely undesirable. Moral: do not make him “grab” air, ignoring the fuel reserve light.
In general, sellers were right - imported pumps are better. They do not buzz, because they are carefully assembled, do not heat up, because all the windings in them are intact, and serve longer because they are equipped with filters. It’s very disappointing - before all this obvious “small things” our products literally have one step left, which, it seems, there is no one to take …
1. Pump 058464044
Bosch firms. Price - 140-160 at. e.
2. Pump 98T092
Firm "Pirburg". Price - 140-160 at. e.
3. Pump 18.3780
Tyumen plant ATE. Price - 32–36 at. e.
4. Pump 50.1139
Stary Oskol plant ATE.
Price - 30–35 at. e.
5. "The Prince (left) and the beggar."
6. Typically, the pump part consists of rollers …
7 …. Pirburg prefers gears.
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