The difference between a dry water meter and a wet water meter
The big difference between a dry water meter and a wet water meter is the metering mechanism. The impeller is separated from the gear, and the upper end of the impeller is coupled with the magnetic element at the lower end of the gear by a magnetic element (magnetic ring or cylindrical magnetic steel). When the water flow pushes the impeller to rotate, the magnetic element at the upper end of the impeller attracts or repels the magnetic element at the lower end of the gear to drive the gear to rotate synchronously, and the transmission counter records the amount of water flowing through the water meter.
1. Magnetic components of dry water meters
The commonly used magnetic materials for dry water meters are ferrite and NdFeB, and the structural shapes of magnetic components generally include ring magnets, columnar magnets, ring magnets and "door" shaped silicon steel sheets.
2. Gear box of dry water meter
The counting mechanism of the dry water meter relies on the gear box to be isolated from the water to be measured, so the bottom of the gear box and its surroundings must be able to withstand the pressure test of 2MPa without deformation. For this reason, when designing a dry water meter, in addition to adding more than ten reinforcing ribs on the upper and lower bottoms of the gear box, the bottom and inner walls of the gear box are often lined with metal bowl-shaped linings to prevent them from being deformed under pressure. .
There is a shaft hole at the upper and lower bottom of the gear box, which is respectively matched with the gear shaft and the impeller shaft. In order to minimize the frictional resistance of the moving parts and increase the initial flow value, a concave (or plane) gem bearing is generally set at the bottom of the upper shaft hole. The counting mechanism of the dry water meter not only isolates the water to be measured by the surrounding and bottom of the gear box, but also takes good sealing measures on the upper part of the gear box to prevent the sewage outside the meter from flowing into the erosion counting mechanism.